Hormone and cytokine circadian alteration in non-small cell lung cancer patients.

Alterations in hormone secretion and cytokine levels have been evidenced in many neoplastic diseases. In this study we have evaluated the circadian profile of growth hormone (GH), insulin-like growth factor-1 (IGF-1), interleukin-2 (IL2), melatonin (MEL) and cortisol (COR) serum levels in non-small cell lung cancer patients. Blood was sampled every 4 h for 24 h in 11 healthy (H) men (ages 35-53 years) and 9 men with stage 2, 3 or 4 non-small cell lung cancer (C) (ages 43-63 years). Serum GH, total IGF1, IL2, MEL and COR were measured and examined for group differences, trends, and rhythm characteristics. 24-h means were significantly higher in C234 vs H for GH, GH/IGF1, IL2 and COR, and lower for IGF1, but IL2 and COR were not different for C23 vs H. A linear regression across 4 groups (H, C2, C3, C4) found a positive trend for COR, GH, GH/IGF1 and IL2, and a negative trend for IGF1. A linear regression run between the 24-h mean levels of GH, IGF1, COR, MEL and IL2 in healthy subjects evidenced a statistically significant positive trend between MEL and GH (R = 0.281, p = 0.022) and in cancer patients showed a statistically significant negative trend between GH and IGF1 (R = 0.332, p = 0.01), COR and IGF1 (R=0.430, p=0.001), and a statistically significant positive trend between the 24-h mean of COR and GH (R = 0.304, p = 0.02). Rhythms in MEL and COR (peaks near 01:00h and 08:00h, respectively) indicated identical synchronization to the light-dark cycle for both groups. A circadian rhythm was detected in GH and GH/IGF1 for C23 and H, with IGF1 and IL2 non-rhythmic in any group. In conclusion, an increasing trend and progressive loss of circadian rhythmicity in GH and GH/IGF1, an increasing trend in cortisol and IL2, and a decreasing trend in IGF1 in C, reflect a complex chain of events that could be involved in progression of neoplastic disease. A therapeutic strategy needs to take into account circadian patterns and complex interactions of the multiple functions that characterize the hormone and cytokine levels in the frame cancer progression.

A timetable of 24-hour patterns for human lymphocyte subpopulations.

Specific lymphocyte cell surface molecules involved in antigen recognition and cell activation present different circadian patterns, with peaks and troughs reflecting a specific time-related compartment of immune cell function. In order to study the dynamics of variation in expression of cytotoxic lymphocyte cell surface molecules that trigger immune responses, several lymphocyte cell surface clusters of differentiation (CD) and antigen receptors, analyses were performed on blood samples collected every 4 h for 24 h from eleven clinically-healthy men. Assays for serum melatonin (peaking at night) and cortisol (peaking near awakening) confirmed 24-h synchronization of the subjects to the light-dark schedule. A significant (p≤0.05) circadian rhythm could be demonstrated for six of the 10 lymphocyte subpopulations, with midday peaks for CD8+dim (T cytotoxic cells, 11:15 h), gammadeltaTCR (gamma-delta T cell receptor-expressing cells, 11:33 h), CD8+ (T suppressor/cytotoxic cells, 12:08 h), and for CD16+ (natural killer cells, 12:59 h), and peaks during the night for CD4+ (T helper/inducer cells, 01:23 h) and CD3+ (total T cells, 02:58 h). A borderline significant rhythm (p = 0.056) was also observed for CD20+ (total B cells), with a peak late in the evening (23:06 h). Acrophases for 3 subsets, CD8+bright (T suppressor cells, 15:22 h), HLA-DR+ (B cells and activated T cells, 23:06 h) and CD25+ (activated T lymphocytes with expression of the alpha chain of IL2 receptor, 23:35 h), where a 24-h rhythm could not be definitively determined, nevertheless provide information on the location of their highest values and possible physiological significance. Thus, specific lymphocyte surface molecules present distinctly-timed profiles of nyctohemeral changes that indicate a temporal (i.e., circadian) organization of cellular immune function, which is most likely of physiological significance in triggering and regulating immune responses. Such a molecular cytotoxic timetable can potentially serve as a guide to sampling during experimental, diagnostic, therapeutic and/or other medical procedures.

A method to evaluate dynamics and periodicity of hormone secretion.

Spontaneous hormone secretory dynamics include tonic and pulsatile components and a number of periodic processes. Circadian variations are usually found for melatonin, TSH and GH, with peak secretions at night, and in cortisol secretion, which peaks in the morning. Free thyroxine (FT4) and insulin-like growth factor (IGF)1 levels do not always change with circadian rhythmicity or show only minor fluctuations. Fractional variations explore the dynamics of secretion related to time intervals, and the rate of change in serum levels represents a signal for the receptorial system and the target organ. We evaluated time-related variations and change dynamics for melatonin, cortisol, TSH, FT4, GH and IGF1 levels in blood samples obtained every 4 h for 24 h from eleven healthy males, ages 35-53 years (mean ∓ SE 43.6 ± 1.7). Nyctohemeral (i.e., day-night) patterns of hormone secretion levels and the fractional rate of variation between consecutive 4-hourly time-qualified hormone serum levels (calculated as percent change from time 1 to time 2) were evaluated for circadian periodicity using a 24 and 12-h cosine model. A circadian rhythm was validated for serum level changes in cortisol with peaks of the 24-h cosine model at 07:48 h, and melatonin, TSH and GH, with phases at 01:35 h, 23:32 h, and 00:00 h, respectively. A weak, but significant, 12-h periodicity was found for FT4 serum levels, with minor peaks in the morning (10:00 h) and evening (22:00 h), and for IGF1, with minor peaks in the morning (07:40 h) and evening (19:40 h). Circadian rhythmicity was found in the 4-hourly fractional variations with phases of increase or surge at 02:00 h for cortisol, 22:29 h for melatonin, 05:14 h for FT4, and 21:19 h for GH. A significant 12-h periodicity was found for the 4-hourly fractional variations of TSH with two peaks in the morning (decrease or drop at 04:42 h) and afternoon (surge at 16:28 h), whereas IGF1 fractional variation changes did not show a significant rhythmic pattern. In conclusion, the calculation of the time-qualified fractional rate of variation allows evaluation of the dynamics of secretion and the specification of the timepoint(s) of maximal change of secretion, not only for hormones whose secretion is characterized by a circadian pattern of variation, but also for hormones that show no circadian or only weak ultradian (12 h) variations (i.e., FT4).

Heart rate response to a standardized walking exercise in the Arctic circumpolar region in morning vs. evening during the polar night and midnight sun.

AIM: Awareness of daytime and/or seasonal variation in performance and exercise efficiency can be important for athletes and coaches in order to suitably plan training sessions and avoid over-training. The study goal was to evaluate and compare walking-speed and time-related heart rate (HR) responses to a walking task at two times of day and year. METHODS: Five healthy females (age 21-35 years) performed 9 km outdoor walking at 09:00h and 18:00h on 4 consecutive days in a period without sunlight (January) and with continuous daylight (May). Walking speed, average-heart rate (HR) and peak-HR (as %HRmax) were compared across all exercise sessions. RESULTS: In January the subjects achieved a higher peak-HR when they trained in the evening vs. morning, while average-HR and walking speed were not modified significantly. In May they achieved a higher peak-HR and kept a higher average-HR when they trained in the morning, under the same walking speed. In both training-times carried out in May, average-HR and peak-HR were lower compared with January, while the walking speed was unvaried. CONCLUSION: A lower exercise average and peak HR, that could potentially be a favourable condition for exercise conditioning, was observed at both daily test times in May vs. January, with overall lowest HR observed in May when exercise occurred at 18:00 h. These findings support the presence of both seasonal and time of day effects on HR responses to a standardized exercise.

Time-related dynamics of variation in core clock gene expression levels in tissues relevant to the immune system.

Immune parameters show rhythmic changes with a 24-h periodicity driven by an internal circadian timing system that relies on clock genes (CGs). CGs form interlocked transcription-translation feedback loops to generate and maintain 24-h mRNA and protein oscillations. In this study we evaluate and compare the profiles and the dynamics of variation of CG expression in peripheral blood, and two lymphoid tissues of mice. Expression levels of seven recognized key CGs (mBmal1, mClock, mPer1, mPer2, mCry1, mCry2, and Rev-erbalpha) were evaluated by quantitative RT- PCR in spleen, thymus and peripheral blood of C57BL/6 male mice housed on a 12-h light (L)-dark (D) cycle and sacrificed every 4 h for 24 h (3-4 mice/time point). We found a statistically significant time-effect in spleen (S), thymus (T) and blood (B) for the original values of expression level of mBmal1 (S), mClock (T, B), mPer1 (S, B), mPer2 (S), mCry1 (S), mCry2 (B) and mRev-Erbalpha (S, T, B) and for the fractional variation calculated between single time-point expression value of mBmal1 (B), mPer2 (T), mCry2 (B) and mRev-Erbalpha (S). A significant 24-h rhythm was validated for five CGs in blood (mClock, mPer1, mPer2, mCry2, mRev-Erbalpha), for four CGs in the spleen (mBmal1, mPer1, mPer2, mRev-Erbalpha), and for three CGs in the thymus (mClock, mPer2, mRev-Erbalpha). The original values of acrophases for mBmal1, mClock, mPer1, mPer2, mCry1 and mCry2 were very similar for spleen and thymus and advanced by several hours for peripheral blood compared to the lymphoid tissues, whereas the phases of mRev-Erbalpha were coincident for all three tissues. In conclusion, central and peripheral lymphoid tissues in the mouse show different sequences of activation of clock gene expression compared to peripheral blood. These differences may underlie the compartmental pattern of web functioning in the immune system.

BLOOD PRESSURE, HEART RATE AND MELATONIN CYCLES SYNCHRONIZATION WITH THE SEASON, EARTH MAGNETISM AND SOLAR FLARES.

Three spectral components with periods of about (~) 0.41, ~0.5 and ~1.0 year had been found with serially independent sampling in human circulating melatonin. The time series consisted of around-the-clock samples collected for 24 hours at 4-hour intervals from different patients over several years. Some of these components had been found to be circadian stage-dependent, the daytime measurements following mostly a circannual variation, whereas a half-year characterized the nighttime samples. The latter were incorporated into a circasemiannual map. The relative brevity of the series prevented a check for the coexistence of all three spectral components, even if each component seemed to have a raison d'être. In time series of transdisciplinary data, a 1.00-year synchronized component is interpreted as representing the seasons. The half-year may qualify the circannual waveform, but it is also a signature of geomagnetics. An ~0.41-year (~5-month) component is the signature of solar flares. It has been called a cis-half-year (cis = on this side of a half-year) and may be detected only intermittently. Charles L. Wolff predicted the existence, among others, of ~0.42- and ~0.56-year components as beat periods of rotations at different solar latitudes.The multiple components characterizing circulating melatonin could also be found in a (to our knowledge unique) data set of a clinically healthy scientist (RBS). Herein, we focus on vascular data self-measured by RBS as he aged from ~20 to ~60 years. A multi-component model consisting of cosine curves with periods of 0.41, 0.50 and 1.00 year was fitted to weekly means of systolic (S) and diastolic (D) blood pressure (BP) and heart rate (HR) collected ~5 times a day over 39 years by RBS. All three components can coexist for a while, although all of them are nonstationary in their characteristics and come and go by the criterion of statistical significance.Intermittently, BP and HR are synchronized selectively with one or the other aspect of RBS' physical environment, namely the seasons (at ~1.0 year), earth magnetism (at ~0.5 year) and/or solar flares (at ~0.42 year). Cosmic-biotic transfer of information, albeit hardly of energy (the biospheric amplitudes are very small) may be mediated in this set of frequency windows. As found earlier, RBS' circulation is also frequency-trapped environmentally in multidecadal windows, HR being locked into the transtridecadal Brückner, or rather Brückner-Egeson-Lockyer, BEL sunspot and terrestrial weather cycle, while his BP follows Hale's didecadal cycle in the changing polarity of sunspots.The ~0.41-year HR cycle may be associated with changes in solar flares, the cis-half-year amplitude of HR showing a cross-correlation coefficient of 0.79 with the total solar flare index (from both solar hemispheres) at a lag of ~3.2 years. The superposed time courses of these two variables indicate the presence of a shared Horrebow-Arago-Schwabe sunspot cycle of ~11 years, the cis-half-year in HR being more prominent after the total solar flare index reaches its ~11-year peak. Differences in the time-varying behavior of BP vs. HR are also described.

Expression of clock genes Per1 and Bmal1 in total leukocytes in health and Parkinson's disease.

BACKGROUND: There is a growing number of clinical studies that revealed a variety of behavioral and physiological desynchronies in patients with Parkinson's disease (PD). However, these desynchronies have not been defined at the molecular level. METHODS: Using real-time RT-PCR assay, we analyzed the expression profiles of two principle clock genes, PER1 and BMAL1, in total leukocytes for 12 h during the evening, overnight and morning in subjects with PD and age/sex-matched healthy controls. RESULTS: A difference in the expression pattern of BMAL1 but not PER1 was apparent during the dark span, where the relative abundance of BMAL1 was significantly lower in PD patients versus control subjects at 21:00, 00:00 and 06:00 h. Furthermore, expression levels of BMAL1 in PD patients correlated with their United Parkinson's Disease Rating Scale score at 06:00, 09:00 h, and with Pittsburgh Sleep Quality Index score at 06:00 h. CONCLUSION: These results suggest that a peripheral molecular clock, as reflected in the dampened expression of the clock genes BMAL1 in total leukocytes, is altered in PD patients. In addition, the relative BMAL1 levels correlate positively with PD severity, which could provide a molecular basis to help monitor disease progression and response to investigational drugs.

In remembrance of Eugene Ladislas Kanabrocki (18 April 1922 * 23 April 2009): a 'General' in the battle of penetrating the normal range and in revealing its relation to the cosmos.

Col. Eugene L. (Gene) Kanabrocki, PhD, commanding officer of the 361st Medical Laboratory of the U.S. Army Reserve, together with Col. Lawrence E. (Larry) Scheving, Professor at the University of Arkansas, initiated in May 1969 a linked cross-sectional (hybrid) study at Fort Sam Houston, TX, to examine the oscillatory (circadian) nature of many physiological variables in a group of 13 army men, 22-28 years of age, anticipating that such data would serve, as indeed they did, as time-specified reference values in future investigations of health and aging. In the initial study, 36 variables were examined around the clock in observations at 3-hour intervals. In subsequent 24-hour profiles, mapped in May of 1971 (mostly on new, young subjects, and not officially part of the Aging Project), 1979, 1988, 1993, 1998 and 2003, additional subjects and variables were included. The follow-up studies were conducted at the Hines VA Medical Center in Hines, Illinois. Of the original 13 subjects, four were measured in all 6 studies and another four in 5 of the 6 studies. Three of the eight became diabetic (Type II) and three had vascular circulatory problems. Presently, a bank of circadian data for 187 medically relevant variables of blood (plasma or serum), saliva, urine, vital signs and other variables on the same subjects covers a span of 34 years. Dr. Robert B. Sothern (RBS), of the University of Minnesota, USA, the major analyst of Gene's investigations, in addition to being an add-on subject as he was in three studies, set up the half-hourly monitoring of blood pressure (BP) and heart rate (HR) in the 2003 study that yielded the data suggesting that the standard deviations (SD) of systolic (S) and diastolic (D) BP and HR are infl uenced by a magnetic storm. Since the standard deviation rather than the amplitude of a vascular spectral component was affected, we may be dealing with a stochastic rather than frequency window-dependent resonance with a magnetic storm. Gene and RBS also found (p< 0.08) an about-decadal signature of solar activity in long-acting natriuretic peptide (LANP), vessel dilator (VSDL), insulin, LH, prolactin, T3 uptake and, most importantly, in melatonin (p=0.004), noted solely to constitute a stimulus for follow-up studies, even when resonance occurs in an anticipated Horrebow-Schwabe circadecadal window gauged by relative sunspot (Wolf) numbers and involves many endocrine variables, as anticipated on the basis of independent evidence in melatonin and cortisol. The wealth of circadian information collected in these studies by Gene constitutes a treasure trove of unique advances in the battle of the normal range, with solid contributions also by Prof. Germaine Cornélissen of the University of Minnesota, USA, and by Prof. Ramon C. Hermida of the University of Vigo, Spain.

Time microscopy of circadian expression of cardiac clock gene mRNA transcription: chronodiagnostic and chrono-therapeutic implications.

BACKGROUND AND PURPOSE: Molecular clocks present in organs and individual cells throughout the body are central for the temporal coordination of internal biological processes among themselves and with external environmental cycles. Relationships between circadian clocks and normal vs. abnormal organ physiology can have significant impact relevant to not only cardiovascular health, but also to the general treatment and prognosis of human disease. Chronobiological statistical procedures were applied to previously published circadian clock gene (CG) mRNA expression data which were described macroscopically, in order to establish rhythm probability and point and interval estimates for amplitudes and acrophases for 14 clock and clock-controlled genes in mouse heart. CGs in general and their importance to cardiovascular health, as well as to diagnosis and treatment of human disease, are reviewed. MATERIALS AND METHODS: Organs from male Balb/c mice were harvested every 4 h for 24-h on the 3rd day in constant darkness and analyzed by quantitative real-time reverse transcription-polymerase chain reaction for 14 CGs: mPer1, mPer2, mPer3, mCry1, mCry2, mBmal1, mCK1delta, mCK1epsilon, mClock, mDbp, mNpas2, mRev-erbalpha, mRev-erbbeta, and mTim. Relative mRNA levels normalized to corresponding G3-PDH RNA levels were re-expressed as percent of the highest value for each CG and analyzed for circadian time effect by one-way ANOVA and for circadian rhythm characteristics by single cosinor. RESULTS: 12 CGs showed a significant time-effect at p < or = 0.031 by ANOVA and 13 CGs displayed a significant 24-h rhythm at p < or = 0.011 by cosinor analysis. Five CGs (mRev-erbalpha, mDbp, mPer1, mRev-erbbeta, mPer3) reached their maxima late in the presumed resting span, 5 CGs (mPer2, mCry2, mCK1delta, mCK1epsilon, mCry1) reached their peak early in the presumed activity span, while 3 genes (mBmal1, mClock, mNpas2) reached their peak late in the presumed activity span. CONCLUSIONS: Macroscopic inspection concluded a robust circadian rhythm in 8 CGs, while cosinor analysis detected significance in 13 of 14 CGs (the developmental gene mTim is usually not circadian rhythmic) and computed point and interval estimates for amplitudes and acrophases, useful in making future objective comparisons among organisms and conditions. Information on statistically-determined rhythm characteristics of the molecular clock presents new avenues for diagnosis and therapeutic intervention in conditions where disturbance of circadian CG expression is an important cause of morbidity in chronic illnesses and diseases with a strong circadian component, including coronary vascular disease.

Circadian characteristics of serum calcium, magnesium and eight trace elements and of their metallo-moieties in urine of healthy middle-aged men.

OBJECTIVE: To monitor the around-the-clock distribution of serum and urine concentrations of calcium, magnesium and eight trace elements and of those same elements in urine after their dialysis, and to statistically describe their circadian characteristics by chronobiological procedures. MATERIALS AND METHODS: Serum and urine samples were collected every 3h over a single 24h period from eleven clinically-healthy male subjects, 41-60 years of age, and were analyzed for calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), cobalt (Co), chromium (Cr), and nickel (Ni). Urines were also sequentially dialyzed against ammonium-barbituric acid buffer at pH 7.35+/-0.02 using a 12.000-14.000 molecular weight exclusion sieve and then reanalyzed for the same elements. Urine concentrations were adjusted by urine volume to reflect a 3h excretion rate. Time-series were analyzed for circadian time-effect by ANOVA and for rhythm characteristics by the single cosinor fitting procedure. RESULTS: The dialysis effectively removed 90% of total solids, 97% of urea, 92% creatinine, 72% uric acid, and essentially all of glucose. It also removed 99% of potassium (K), 96% of sodium (Na), 65% of Ca and P, 55% of Mg, 41% of Zn and 88% of Ni. A significant or borderline-significant 24h rhythm in serum was detected for Ca, Mg, Fe, Cu, Zn, Cd and Cr; in untreated urine for Ca, Fe, Cu, Zn, Ni, creatinine and volume; and in dialyzed urine for Ca, Fe, Cu, Zn, Pb, Cr, Cd and Ni. A 12h component was significant or borderline-significant in serum for Mg, Fe, Zn, and Cd; in untreated urine for volume, creatinine, Ca, Mg, Cu, and Ni; and in dialyzed urine for Ca, Mg, Fe, Cu, Zn, and Cr. In general, values in serum were lowest near the onset of sleep and highest in the first half of the day (between 02:28 and 13:56 h), while highest values in untreated or dialyzed urine were found several hours later in the day and at night. CONCLUSIONS: Significant circadian variations were found in levels of nearly every element that was measured in blood and urine of 11 healthy men, but with highest and lowest levels occurring at different times. This suggests not only that urine concentrations need to be adjusted for collection time interval and urine volume, but that different biological limits at different times of the 24h day should be applied for serum and urinary monitoring of trace elements. We also found that the non-dialyzable segments of these elements in urine represent metallo-moieties composed of proteinacious matter greater than 12,000-14,000 Daltons. Further studies would be of interest to reveal time specificity for metabolic functions associated with any of these trace elements.

Creatinine clearance and blood pressure: a 34-year circadian study.

BACKGROUND AND OBJECTIVE: The first circadian study of the 361st Medical Laboratory, USAR, was conducted in May 1969 during the Annual Military Training at Brook Army Hospital, Fort Sam Houston, Texas. The study was approved by the Surgeon General, 5th US Army, and was designed to establish a circadian database for 63 medically relevant variables of 13 young members of the Unit. The subsequent studies, all in the month of May, in 1979, 1988, 1993,1998, and 2003, followed the same protocol and were conducted at Edward Hines Jr., Veterans Administration Hospital, after approval by Human Studies Subcommittees. Since a reduction in Creatinine Clearance (CrCl) to the level of 60 ml/min/1.73m2 signals the onset of kidney malfunction and since a concurrent increase in blood pressure (BP) >140/90 mm Hg, contributes greatly to an unfavorable cardiovascular prognosis, it seemed prudent to examine possible changes in these and in other relevant variables in a group of young Army men, which may have developed over a 34 year period of time. MATERIAL AND METHODS: Thirteen US Army male volunteers (23-27y of age) served as subjects in the 1969 study. A majority of these men, two additional Army men and two non-military subjects, participated in subsequent studies: 1979 (7,2,1), 1988 (8,2,1), 1993 (5,4,1), 1998 (7,2,2), 2003 (7,2,1). In each study, subjects were admitted to a hospital ward, were given medical examination including a 12-lead electrocardiogram and followed the same Protocol. Lights "OUT" at 22:30h and "ON" at 06:30h. The meals, hospital 2400-calorie diets, were served at 17:30, 07:30 and at 13:30h. Vital signs were measured immediately after each 3h urine collections, around the clock, and bloods were collected every 3h. Blood, plasma, serum, saliva and urines were analyzed for numerous analytes including creatinine, using automated laboratory systems. Kidney functions were assessed using the measured and estimated glomerular filtration rates. RESULTS: Over the 34y study span, 16 men provided sixty-one 24h profiles for CrCl-related variables (urine volume, creatinine, and serum creatinine) and fifty-eight profiles for BP. Using all normalized data, a significant circadian rhythm was found for each of these variables. Significant circadian variations in SBP, DBP, serum and urine creatinine, and urine volume, were evident with peak levels, on average, occurring in the evening hours. CONCLUSIONS: In healthy subjects, age was associated with an increase in SBP and urine volume and with a decrease in urine creatinine. In diabetic subjects, aging was associated with increases in both blood pressure and Creatinine Clearance. It is interesting to note that for the 3 subjects who at a later date developed diabetes, the CrCl levels were higher than the 5 age-matched controls during each study year, over the entire 34y observation span, including the period prior to diagnosis. Clin Ter 2008; 159(6):409-417.

Relationships between 24h observations in intraocular pressure vs blood pressure, heart rate, nitric oxide and age in the medical chronobiology aging project.

OBJECTIVE: To evaluate associations between intraocular pressure (IOP) and blood pressure (BP), heart rate (HR), serum nitric oxide (NO), diurnal variations, diabetes and aging in data collected during 24h studies of men conducted over 34y. MATERIALS AND METHODS: As part of the Medical Chronobiology Aging Project, male Army veterans, ages 22 to 81y, without a history of eye disease, were studied around-the-clock in May 1969 (n = 13), 1979 (n = 11), 1988 (n = 11), 1993 (n = 11), 1998 (n =12) and 2003 (n = 10). Measurements of IOP (R & L eyes, supine position), BP and HR (sitting position), and collection of blood were obtained every 3h (8 readings/24h) from 19:00h to 16:00h the next day. Individual time series were analyzed for circadian characteristics by the least-squares fit of a 24& 12h cosine. After normalizing all data to percent of mean to reduce inter-subject variability in levels, grouped data were analyzed for time-effect by ANOVA and for circadian rhythm by multiple component (24h&12h) cosine fitting. Individual 24h averages were analyzed by simple and multiple regression for relationships between IOP and systemic variables, diabetic status and age. RESULTS: Over the 34y study span, 22 men provided sixty-three 24h profiles for IOP & HR, 61 for BP, and 21 for NO. Using all normalized data, a significant circadian rhythm was found for each variable at p <0.001. Circadian peaks (orthophases) are located in the late morning for IOP-R (10:20h) and IOP-L (10:52h), and in the evening for HR (18:52h), NO (20:00h), SBP (20:40h) and DBP (21:44h). An out-of-phase relationship of about 10h is noted on a group basis between IOP vs BP, HR and NO. The locations of individual circadian peaks for IOP-R were found around the clock, but with a significant predominance between 10:00 and 16:00h (day type), and 04:00-10:00h (morning type). In contrast, BP, HR and NO showed a significant clustering of evening type or night type peaks. The overall mean IOP for the right eye was slightly, but not significantly, higher than the left eye (17.60+/-0.21 vs 17.34+/-0.18 mmHg; p = 0.385), with a strong positive correlation between both eyes (R = 0.952, p <0.0001). IOP showed a significant positive correlation with SBP (R = 0.49, p <0.001), diabetic status (R = 0.47, p <0.001), age (R = 0.32, p = 0.011), and HR (R = 0.28, p = 0.031). A multiple regression using SBP, DBP, HR, age and diabetic status (5 men became diabetic over the 34y study span) as independent variables resulted in SBP being the strongest predictor of IOP (p = 0.0001), followed by DBP (p = 0.0103). After adjustment for BP, independent effects of age (p = 0.187), HR (p = 0.789) and diabetic status (p = 0.153) were eliminated from the prediction equation. CONCLUSIONS: The results of these studies reveal significant circadian variations in IOP, BP, HR and NO, with peak levels, on average, near noon for IOP and in the evening for BP, HR and NO. An increase in SBP was associated with an increase in IOP. While SBP and DBP are significant predictors of IOP levels, single measurements during regular clinic hours may not reveal the full functional relationship between the variables measured in our studies. Therefore, circadian information on total 24h patterns may contribute to the reliability of diagnosis and guide proper individualized timing of optimal patient management (e.g., for glaucoma, hypertension, diabetes, among other conditions).

Circadian distribution of iron and ferritin in serum of healthy and type 2 diabetic males.

AIM: We examined the circulating levels of iron and ferritin in serum of seven healthy and three insulin non-dependent diabetic (Type 2) males in order to compare their circadian characteristics. METHODS: Blood samples were collected every 3h over a 24h period and were analyzed for serum iron and ferritin. RESULTS: The mean Fe level was significantly higher in healthy than in diabetic subjects: 80.0 +/- 3.3 vs. 63.0 +/- 3.7 microg/dL. The ferritin level was significantly lower in healthy than in diabetic men: 79.8 +/- 4.7 vs. 186.3 +/- 110.5 microg/L. A significant (p < 0.001) time-effect was found by ANOVA and circadian rhythm was detected at p < 0.001 in all data sets when a 24h cosine was fitted to the normalized data. Acrophases were located in mid to late morning for Fe (11:30, vs. 09:22h) and for ferritin (11:10 vs. 11:46h). DISCUSSION: We concluded that there is significant circadian variation in both serum Fe and ferritin, with predictable peaks in the mid to late morning.

CIRCANNUAL VARIATION IN HUMAN DIASTOLIC BLOOD PRESSURE DURING CONSECUTIVE SOLAR CYCLES.

Putative circadecadal modulations of a circannual variation in diastolic blood pressure are explored in a still accumulating 35 year record of self-measurements by a clinically healthy man. Analyses of monthly means by gliding spectra, one-way analysis of variance (ANOVA), and cosinor were carried out after removing data collected during travel across time zones or during illness. An about yearly change in diastolic blood pressure may or may not be detected with statistical significance by cosinor or ANOVA, apparently as a function of solar cycle number and/or stage. It appears to be, however, 1 year synchronized in the entire span analysed as a whole. A given variable such as diastolic blood pressure may be characterized by multifrequency rhythms that may intermodulate, so that findings in different stages of cycles with the lowest (e.g., circadecadal) frequency mapped may determine different outcomes in cycles with higher frequencies, such as circannuals.

Multiple resonances among time structures, chronomes, around and in US. Is an about 1.3-year periodicity in solar wind built into the human cardiovascular chronome?

AIMS: Velocity changes in the solar wind, recorded by satellite (IMP8 and Wind) are characterized by a solar cycle dependent approximately 1.3-year component. The presence of any approximately 1.3-year component in human blood pressure (BP) and heart rate (HR) and in mortality from myocardial infarction (MI) is tested and its relative prominence compared to the 1.0-year variation. MATERIALS AND METHODS: Around the clock manual or automatic BP and HR measurements from four subjects recorded over 5 to 35 years and a 29-year record of mortality from MI in Minnesota were analyzed by linear-nonlinear rhythmometry. Point and 95% confidence interval (CI) estimates were obtained for the approximately 1.3-year period and amplitude. The latter is compared with the 1.0-year amplitude for BP and HR records concurrent to the solar data provided by one of us (JDR). RESULTS: An approximately 1.3-year component is resolved nonlinearly for MI, with a period of 1.23 (95% CI: 1.21; 1.26) year. This component was invariably validated with statistical significance for BP and HR by linear rhythmometry. Nonlinearly, the 95% CI for the 1.3-year amplitude did not overlap zero in 11 of the 12 BP and HR series. Given the usually strong synchronizing role of light and temperature, it is surprising that 5 of the 12 cardiovascular series had a numerically larger amplitude of the 1.3-year versus the precise 1.0-year component. The beating of the approximately 1.3-year and 1.0-year components was shown by gliding spectra on actual and simulated data. DISCUSSION AND CONCLUSION: The shortest 5-year record (1998-2003) revealed an approximately 1.3-year component closer to the solar wind speed period characterizing the entire available record (1994-2003) than that for the concurrent 5-year span. Physiological variables may resonate with non-photic environmental cycles that may have entered the genetic code during evolution.

Rhythmic variations in pain, stiffness, and manual dexterity in hand osteoarthritis.

OBJECTIVE: To explore circadian variation in pain, stiffness, and manual dexterity in patients with hand osteoarthritis (OA). METHODS: Twenty one patients with hand OA, as defined by ACR criteria (17 women, four men, mean age 62.2 years, range 52-74 years) self rated pain and stiffness on separate 10 cm horizontal visual analogue scales and performed bead intubation coordinometry (BIC) six times each day (on waking up, at bedtime, and every four hours in between) for 10 consecutive days. Each series (using data with the trend removed if there was a significant trend) was analysed for circadian rhythmicity by a cosine vector technique (single cosinor). With individual data expressed as the percentage of the mean, group rhythm characteristics at period 24 hours were summarised for each variable by population mean cosinor analysis. RESULTS: Individual analyses identified significant circadian rhythms at p

Non-linear relation of heart rate variability during exercise recovery with local geomagnetic activity.

Heart rate variability (HRV) during 30 minute's recovery from a 30-minute exercise was established for 6 healthy men 23-30 years old. The exercise-recovery schedule was performed at 8 circadian stages over 11 days for each subject and analyzed over consecutive 5-minute segments. The local K index for the time of the recovery was recorded as a variable for geomagnetic activity. Pooling all HRV values across the different times into recovery, the relation of HRV to local K is found to be non-linear. A quadratic model fitted to the pooled HRV values is statistically significant. The present study indicates that during recovery from exercise, the effect of geomagnetic disturbances on HRV is non-linear. A non-linear relation of HRV with respect to geomagnetic activity deserves further work to determine whether it can account for discrepant findings of an effect of magnetic storms on the incidence of myocardial infarctions, for which a decreased HRV is a predictor.

Circadian expression of clock genes in human oral mucosa and skin: association with specific cell-cycle phases.

We studied the relative RNA expression of clock genes throughout one 24-hour period in biopsies obtained from the oral mucosa and skin from eight healthy diurnally active male study participants. We found that the human clock genes hClock, hTim, hPer1, hCry1, and hBmal1 are expressed in oral mucosa and skin, with a circadian profile consistent with that found in the suprachiasmatic nuclei and the peripheral tissues of rodents. hPer1, hCry1, and hBmal1 have a rhythmic expression, peaking early in the morning, in late afternoon, and at night, respectively, whereas hClock and hTim are not rhythmic. This is the first human study to show a circadian profile of expression for all five clock genes as documented in rodents, suggesting their functional importance in man. In concurrent oral mucosa biopsies, thymidylate synthase enzyme activity, a marker for DNA synthesis, had a circadian variation with peak activity in early afternoon, coinciding with the timing of S phase in our previous study on cell-cycle timing in human oral mucosa. The major peak in hPer1 expression occurs at the same time of day as the peak in G(1) phase in oral mucosa, suggesting a possible link between the circadian clock and the mammalian cell cycle.

Near 10-year and longer periods modulate circadians: intersecting anti-aging and chronoastrobiological research.

Biological cycles with relatively long and some unusual periods in the range of the half-week, the half-year, years, or decades are being discovered. Their prior neglect constituted a confounder in aging and much other research, which then"flew blind" concerning the uncertainties associated with these cycles when they are not assessed. The resolution of more about 10-year and other cycles, some reported herein, replaces the admission of complete unpredictability, implied by using the label "secularity." Heretofore unaccounted-for variability becomes predictable insofar as it proves to be rhythmic and is mapped systematically to serve as a battery of useful reference values. About 10-year cycles in urinary 17-ketosteroid excretion and in heart rate and its variability, among others, are aligned with cycles of similar length in mortality from myocardial infarction. Associations accumulate between cycles of natural physical time structures, chronomes such as the 10.5-year (circadecennian) Schwabe and the 21-year (circavigintunennian) Hale cycles of solar activity, and chronomes in biota. There are about 50-year (circasemicentennian) cycles in mortality from stroke in Minnesota and in the Czech Republic and also in human morphology at birth, the latter result reducing the likelihood that these cycles are purely human made. Associations among large populations warrant long-term systematic coordinated sampling of natural physical and biological variables of interest for the design of countermeasures against already documented elevated risks of stroke, myocardial infarction, and other catastrophic diseases, notably in elderly adults. New findings will be introduced against the background of the documented value of mapping rhythms in medicine and gerontology. In both these fields, rhythms promise the seeming paradox of better care for less.