Effects of melatonin on blood pressure, arterial stiffness and quality of life in postmenopausal women: A randomized controlled trial.

OBJECTIVES: Studies suggest that melatonin may promote cardiovascular protection. Previous trials have primarily been performed on co-morbid patients. Little information exist on the effect in postmenopausal women with general good health. DESIGN, PARTICIPANTS AND INTERVENTION: In a double-blinded placebo-controlled study, we randomized 41 postmenopausal women to either 10 mg melatonin per day or placebo for 3 months. OUTCOME MEASURES: Outcomes of the trial was changes in blood pressure, pulse wave velocity (PWV), and quality of sleep evaluated by Pittsburgh Sleep Quality Index (PSQI). RESULTS: Thirty-nine women completed the study. Mean age was 63 years (range 55-75 years). Over the 3 months of the trial, PWV did not differ between groups: Placebo 1.1% (IQR -2.1;9.9) vs. melatonin 0.0% (IQR-9.8;4.1), p = 0.43). The were no significant differences in blood pressure bewteen melatonin and placebo group. Both groups had a pour quality of sleep at baseline (placebo: PSQI 6.0 (IQR 3.3; 8.8) vs. melatonin PSQI 6.0 (IQR 3.0; 10.0), p = 0.94), which did not change in response to treatment. CONCLUSION: In healthy postmenopausal women, supplementation with 10 mg melatonin was well-tolerated, but we did not observe any significant improvements in pulse wave velocity, blood pressure or quality of sleep compared with placebo.

Reduced fat mass and increased lean mass in response to 1 year of melatonin treatment in postmenopausal women: A randomized placebo-controlled trial.

OBJECTIVE: Apart from regulating the circadian rhythm, melatonin exerts a variety of actions in the living organism. Among these functions, melatonin is believed to have a positive effect on body weight and energy metabolism. So far, the evidence for this relies mainly on animal models. In this study, we aimed to determine the effects of melatonin on body composition, lipid and glucose metabolism in humans. DESIGN/METHODS: In a double-blind, placebo-controlled study, we randomized 81 postmenopausal women to 1 year of treatment with melatonin (1 or 3 mg nightly) or placebo. Body composition was measured by DXA. Measures were obtained at baseline and after 1 year of treatment along with leptin, adiponectin and insulin. Markers of glucose homeostasis were measured at the end of the study. RESULTS: In response to treatment, fat mass decreased in the melatonin group by 6·9% (95% CI: 1·4%; 12·4%, P = 0·02) compared to placebo. A borderline significant increase in lean mass of 5·2% was found in the melatonin group compared to placebo (3·3%, (IQR:-1·7; 6·2) vs -1·9%, (IQR: -5·7; 5·8), P = 0·08). After adjusting for BMI, lean mass increased by 2·6% (95% CI: 0·1; 5·0, P = 0·04) in the melatonin group. Changes in body weight and BMI did not differ between groups. Adiponectin increased borderline significantly by 21% in the melatonin group compared to placebo (P = 0·08). No significant changes were observed for leptin, insulin or markers of glucose homeostasis. CONCLUSION: Our results suggest a possibly beneficial effect of melatonin on body composition and lipid metabolism as 1 year of treatment reduces fat mass, increases lean mass and is associated with a trend towards an increase in adiponectin.

Inverse Correlation at the Hip Between Areal Bone Mineral Density Measured by Dual-Energy X-ray Absorptiometry and Cortical Volumetric Bone Mineral Density Measured by Quantitative Computed Tomography.

Quantitative computed tomography (QCT) is considered to measure true volumetric bone mineral density (vBMD; mg/cm3) and enables differentiation between cortical and trabecular bone. We aimed to determine the value of QCT by correlating areal BMD (aBMD) by dual-energy X-ray absorptiometry (DXA) with vBMD when using a fixed threshold to delineate cortical from trabecular bone. In a cross-sectional study, 98 postmenopausal women had their hip scanned by DXA and by QCT. At the total hip and the trabecular bone compartment, aBMD correlated significantly with vBMD (r=0.74 and r=0.63; p<0.01, respectively). A significant inverse correlation was found between aBMD and cortical vBMD (r=-0.57; p<0.01). Total hip volume by QCT did not change with aBMD. However, increased aBMD was associated with a decreased trabecular bone volume (r=-0.36; p<0.01) and an increased cortical volume (r=0.69; p<0.01). Changing the threshold used to delineate cortical from trabecular bone from default 350 mg/cm3 to either 300 or 400 mg/cm3 did not affect integral vBMD (p=89) but had marked effects on estimated vBMD at the cortical (p<0.001) and trabecular compartments (p<0.001). Furthermore, increasing the threshold decreased cortical thickness (p<0.001), whereas the strength parameter in terms of buckling ratio increased (p<0.001). Our results show good agreement between aBMD and integral vBMD. However, using a fixed threshold to differentiate cortical from trabecular bone causes an apparent increase in cortical volume with a decrease in cortical density as aBMD increases. This may be caused by the classification of a larger part of the transition zone as cortical bone with increased aBMD.

Association between bone indices assessed by DXA, HR-pQCT and QCT scans in post-menopausal women.

Quantitative computed tomography (QCT), high-resolution peripheral QCT (HR-pQCT) and dual X-ray absorptiometry (DXA) scans are commonly used when assessing bone mass and structure in patients with osteoporosis. Depending on the imaging technique and measuring site, different information on bone quality is obtained. How well these techniques correlate when assessing central as well as distal skeletal sites has not been carefully assessed to date. One hundred and twenty-five post-menopausal women aged 56-82 (mean 63) years were studied using DXA scans (spine, hip, whole body and forearm), including trabecular bone score (TBS), QCT scans (spine and hip) and HR-pQCT scans (distal radius and tibia). Central site measurements of areal bone mineral density (aBMD) by DXA and volumetric BMD (vBMD) by QCT correlated significantly at the hip (r = 0.74, p < 0.01). Distal site measurements of density at the radius as assessed by DXA and HR-pQCT were also associated (r = 0.74, p < 0.01). Correlations between distal and central site measurements of the hip and of the tibia and radius showed weak to moderate correlation between vBMD by HR-pQCT and QCT (r = -0.27 to 0.54). TBS correlated with QCT at the lumbar spine (r = 0.35) and to trabecular indices of HR-pQCT at the radius and tibia (r = -0.16 to 0.31, p < 0.01). There was moderate to strong agreement between measuring techniques when assessing the same skeletal site. However, when assessing correlations between central and distal sites, the associations were only weak to moderate. Our data suggest that the various techniques measure different characteristics of the bone, and may therefore be used in addition to rather than as a replacment for imaging in clinical practice.

The effect of melatonin treatment on postural stability, muscle strength, and quality of life and sleep in postmenopausal women: a randomized controlled trial.

BACKGROUND: Melatonin is often used as a sleeping aid in elderly adults. As previous studies suggest a protective role of melatonin against osteoporosis, it is important to document its safety. Treatment should not cause any hangover effect that could potentially lead to falls and fractures. We therefore aimed to evaluate the effect of melatonin on balance- and muscle function. METHODS AND PATIENTS: In a double-blind placebo-controlled study, we randomized 81 postmenopausal women with osteopenia to receive 1 or 3 mg melatonin, or placebo nightly for 12 months. Postural balance as well as muscle function was measured. In addition, we assessed quality of life and sleep at baseline and after 12 months treatment. RESULTS: Compared to placebo, one-year treatment with melatonin did not affect postural balance or risk of falls. Furthermore, no significant changes between groups were observed in muscle strength in neither upper- nor lower extremities. Treatment did not affect quality of life or sleep. However, in the subgroup of women with sleep disturbances at baseline, a trend towards an improved sleep quality was seen (p = 0.08). CONCLUSION: Treatment with melatonin is safe in postmenopausal women with osteopenia. There is no hangover effect affecting balance- and muscle function following the intake of melatonin. In women with a good quality of sleep, melatonin has no effect, however in poor quality of sleep, small doses of melatonin trended towards improving the quality. TRIAL REGISTRATION: (# NCT01690000).

Melatonin improves bone mineral density at the femoral neck in postmenopausal women with osteopenia: a randomized controlled trial.

Melatonin is known for its regulation of circadian rhythm. Recently, studies have shown that melatonin may have a positive effect on the skeleton. By increasing age, the melatonin levels decrease, which may lead to a further imbalanced bone remodeling. We aimed to investigate whether treatment with melatonin could improve bone mass and integrity in humans. In a double-blind RCT, we randomized 81 postmenopausal osteopenic women to 1-yr nightly treatment with melatonin 1 mg (N = 20), 3 mg (N = 20), or placebo (N = 41). At baseline and after 1-yr treatment, we measured bone mineral density (BMD) by dual X-ray absorptiometry, quantitative computed tomography (QCT), and high-resolution peripheral QCT (HR-pQCT) and determined calciotropic hormones and bone markers. Mean age of the study subjects was 63 (range 56-73) yr. Compared to placebo, femoral neck BMD increased by 1.4% in response to melatonin (P < 0.05) in a dose-dependent manner (P < 0.01), as BMD increased by 0.5% in the 1 mg/day group (P = 0.55) and by 2.3% (P < 0.01) in the 3 mg/day group. In the melatonin group, trabecular thickness in tibia increased by 2.2% (P = 0.04), and volumetric bone mineral density (vBMD) in the spine, by 3.6% (P = 0.04) in the 3 mg/day. Treatment did not significantly affect BMD at other sites or levels of bone turnover markers; however, 24-hr urinary calcium was decreased in response to melatonin by 12.2% (P = 0.02). In conclusion, 1-yr treatment with melatonin increased BMD at femoral neck in a dose-dependent manner, while high-dose melatonin increased vBMD in the spine. Further studies are needed to assess the mechanisms of action and whether the positive effect of nighttime melatonin will protect against fractures.

Muscle function is impaired in patients with "asymptomatic" primary hyperparathyroidism.

BACKGROUND: Patients with "asymptomatic" primary hyperparathyroidism (PHPT) often describe improvement after surgery. METHODS: We evaluated muscle and balance function, quality of life (QoL), and well-being in 58 PHPT patients and 58 population-based matched controls in a cross-sectional study. We tested whether patients considered "asymptomatic" according to international guidelines have functional impairment. RESULTS: Mean age of the patients and controls was 59 years, and 47 (81 %) were women. Patients had higher levels of plasma PTH and ionized calcium. Creatinine and 25-hydroxyvitamin D levels did not differ between groups. Altogether, 16 (28 %) patients were "asymptomatic." Compared with controls, PHPT was associated with significantly lower QoL in all eight domains of the short form-36 questionnaire, lower well-being (WHO Five Well-Being Index; p < 0.001), and impaired postural stability during normal standing with eyes open (p < 0.05) or closed (p < 0.001). Maximum isometric muscle strength was reduced in both upper (p < 0.01) and lower (p < 0.001) extremities. Physical performance was decreased during 10 repeated chair stands (p < 0.001) and time to walk 3 m forward and back (p < 0.05). Restricting analyses to "asymptomatic" patients showed significantly lower muscle strength at knee extension and flexion and impaired postural stability than in matched controls. CONCLUSIONS: PHPT is associated with deleterious effects on muscles and QoL. Impairments also apply to patients with mild disease, normally considered "asymptomatic." This may explain why "asymptomatic" patients report improvements following surgery. The impaired muscle function may contribute to increased fracture risk independent of bone mineral density.

PTH(1-84) replacement therapy in hypoparathyroidism: a randomized controlled trial on pharmacokinetic and dynamic effects after 6 months of treatment.

Untreated, hypoparathyroidism (hypoPT) is a state of hypocalcemia with inappropriately low plasma parathyroid hormone (PTH) levels and hyperphosphatemia. PTH administration normalizes plasma calcium and phosphate levels and reduces the doses of calcium and active vitamin D analogues needed. To develop an evidence-based clinical algorithm to monitor hypoPT patients treated with recombinant human PTH (rhPTH[1-84]) injected subcutaneously in the thigh, we performed a 24-hour monitoring study of pharmacokinetic and pharmacodynamic effects in a group of 38 patients who had completed a 6-month randomized study on effects of treatment with a fixed rhPTH(1-84) dose of 100 µg/d or similar placebo as an add-on to conventional treatment. PTH levels rose immediately, reaching a median peak level of 26.5 (interquartile range [IQR], 20.1-42.5) pmol/L 15 minutes following injection. Thereafter, levels gradually decreased until reaching predosing levels after 16 hours, with a plasma half-life of 2.2 (1.7-2.5) hours. rhPTH(1-84) changed the diurnal rhythms of ionized calcium levels and 1,25-dihydroxyvitamin D (1,25[OH]2 D) levels, with rising levels following injection. Ionized calcium peaked after 7.0 (5.0-10.0) hours. Asymptomatic hypercalcemia was present in 71% of the rhPTH(1-84)-treated patients. Compared with placebo, 24-hour urinary calcium, phosphate, and magnesium did not change, although the diurnal variation in renal excretion rates changed significantly in response to treatment. In conclusion, as a safety precaution, we recommend occasionally measuring calcium levels at approximately 7 hours after administration in order to reveal episodes of hypercalcemia. A 100-µg daily dose of rhPTH(1-84) appears to be too high in some patients, suggesting a need for a device allowing for individual dose adjustments.

Further insights into the pathogenesis of primary hyperparathyroidism: a nested case-control study.

CONTEXT: The pathogenesis of primary hyperparathyroidism (PHPT) is largely unknown. OBJECTIVE: The objective of the study was to ascertain the plasma levels of calcium, PTH, and 25-hydroxyvitamin D (25OHD) as measured prior to a clinical diagnosis of PHPT. STUDY SUBJECTS: Within three population-based cohorts, we identified participants diagnosed with PHPT after their inclusion. Cases (n = 117) were compared with age, gender, and season-matched controls (n = 233). RESULTS: Time from inclusion until a diagnosis of PHPT was median 5.6 yr. Parathyroidectomy was performed in 97%. At the cohort inclusion, undiagnosed PHPT was present in 63% of the cases. Among those without PHPT at inclusion (n = 43), 55% had normocalcemic hyperparathyroidism (vs. 21% in the matched controls, P < 0.01), and 31% had normoparathyroid hypercalcemia. Overall, 25OHD levels were lower in the cases. Compared with their matched controls, 25OHD levels were lower in normocalcemic hyperparathyroidism but not in normoparathyroid hypercalcemia. An adenoma was removed from 78% of the cases with normocalcemic hyperparathyroidism, whereas 39% of the cases with normoparathyroid hypercalcemia had parathyroid hyperplasia (P = 0.02). Overlap performance showed a positive predictive value for later PHPT of 95% for plasma calcium levels greater than 2.52 mmol/liter. Excluding cases with vitamin D insufficiency, the positive predictive value for later PHPT was 83% for PTH levels greater than 5.0 pmol/liter. CONCLUSION: Years prior to a clinical diagnosis of PHPT, calcium homeostasis shows signs of perturbations. Latent PHPT may be characterized by either normocalcemic hyperparathyroidism or normoparathyroid hypercalcemia. Such patients should be offered long-term follow-up to ascertain whether their biochemical profile represents an early state of PHPT.

Patients with surgically cured primary hyperparathyroidism have a reduced quality of life compared with population-based healthy sex-, age-, and season-matched controls.

OBJECTIVE: Primary hyperparathyroidism (PHPT) is associated with feelings of fatigue and depression, as well as limitation to physical and mental functioning. These quality of life (QoL) characteristics improve after parathyroidectomy. However, whether former patients fully regain QoL compared with healthy controls is largely unknown. DESIGN AND PATIENTS: Cross-sectional study. Fifty-one former PHPT patients, successfully treated by surgery (mean time since parathyroidectomy 7.4 (range 5-15) years), and 51 sex- and age-matched healthy controls. METHODS: The 36-item Short-Form Health Survey version 2 and the WHO-Five Well-being Index. The surveys included questions on overall physical and mental health, functioning, and limitation in daily life activities. RESULTS: Former patients scored significantly lower compared with controls in physical functioning (P=0.01), role limitation caused by emotional problems (P=0.01), vitality (P<0.001), and general health (P=0.01). Compared with the controls, cases had a lower median (interquartile range) score of physical component summary (PCS; 54.9 (47.9-58.7) vs 49.6 (45.2-55.9), P=0.03) and mental component summary (MCS; 55.4 (49.7-58.1) vs 52.5 (44.7-55.5), P=0.04). There was no association between time since operation and PCS or MCS. Compared with controls, cases had higher body mass index (BMI; 26.0±4.7 vs 28.8±6.0 kg/m(2), P<0.001) and a higher frequency of cardiovascular diseases (CVD; 41.2 vs 62.7%, P=0.03). After adjustment for differences in BMI and CVD, PCS did no longer differ between groups. However, adjustments did not change the finding of a lower MCS in cases compared with controls. CONCLUSION: Even though QoL may improve substantially after surgery, former PHPT patients still have reduced QoL compared with healthy controls.

Vitamin D status, physical performance and body mass in patients surgically cured for primary hyperparathyroidism compared with healthy controls - a cross-sectional study.

OBJECTIVE: Low plasma 25-hydroxyvitaminD (25OHD) levels, reduced muscle strength and increased body mass index (BMI) are well-known characteristics of primary hyperparathyroidism (PHPT). Mechanisms for low 25OHD levels, increased BMI and potential changes after parathyroidectomy are unknown. Muscle strength is reported to increase following surgical cure, but whether the improvement corresponds to healthy controls' performances remains largely unknown. PATIENTS: We studied 51 patients with former PHPT [mean age 61(36-77) years] successfully treated by surgery [mean time since operation 7·4(5-15) years] and 51 sex- and age-matched controls. MEASUREMENTS: Physical performance include "repeated chair stand" (RCS), "timed up and go" (TUG), muscle strength [hand grip, elbow flexion/extension and knee flexion/extension (60°/90°)], postural stability, biochemistry and anthropometric indices. RESULTS: Forty-one cases had pathologically verified adenoma, three had hyperplasia and three had uncertain diagnosis whereas four had missing data. Dietary calcium intake, vitamin D supplementation and biochemistry including PTH and 25OHD levels did not differ between groups. Former patients had significantly higher BMI (28·8 ± 6·0 kg/m²) than controls (26·0 ± 4·7kg/m²). Muscle pain was more frequently reported by cases than controls, and cases performed RCS slower than controls (P = 0·02). Furthermore, female cases had lower muscle strength in knee flexion 60° (P = 0·02) and 90° (P = 0·05). Former patients no longer differed from controls after adjustment for BMI. CONCLUSION: Following cure, 25OHD levels are normalized suggesting 25OHD insufficiency is not a constitutional characteristics in patients with PHPT. Increased BMI seems to be sustained. Whether this is caused by decreased muscle strength or reduced muscular performance causes adiposity needs further investigations.

Effects of smoking on severity of disease in primary hyperparathyroidism.

In healthy subjects, smoking is associated with lower plasma levels of parathyroid hormone (PTH) and decreased bone mineral density (BMD). The effect of smoking on PTH, skeletal metabolism, and size/histology of the parathyroid glands in primary hyperparathyroidism (PHPT) is unknown. We investigated, in a cross-sectional study, whether smoking affects PTH levels, BMD, and weight/histology of removed parathyroid tissue in PHPT. We studied 344 (285 women) parathyroidectomized patients with PHPT (24% smokers). Biochemistry was determined at the time of diagnosis. BMD was measured before and after surgical cure. Smoking was associated with lower PTH (9.9 ± 1.8 [SD] vs. 12.2 ± 1.8 pmol/l, P < 0.01) and higher phosphate (0.95 ± 0.17 vs. 0.86 ± 0.17 mmol/l, P < 0.01) levels. Adjustments for between-group differences in age, sex, body weight, plasma creatinine, and 25-hydroxyvitamin D (25OHD) levels did not change the findings. Neither weight of removed adenomatous and hyperplastic tissue nor BMD differed according to smoking status. After adjustment for body weight, age, sex, and 25OHD levels, smokers had slightly lower BMD at the whole body but not at the spine, hip, or forearm. Independent of smoking status, surgical cure caused a significant increase in BMD at all measurement sites. In PHPT smoking is associated with lower plasma PTH and higher phosphate levels. Adjustment for confounders of PTH did not change the results. In contrast to healthy subjects, smoking seems not to decrease BMD in PHPT. Smoking may compromise the correct diagnostic evaluation of borderline hyperparathyroidism. It is unknown to what extent smoking in PHPT affects fracture risk and indication for surgery.