Association of change in physical activity and body weight with quality of life and mortality in colorectal cancer: a systematic review and meta-analysis.

PURPOSE: A systematic review and a meta-analysis were performed to assess the associations between change over time in physical activity and weight and quality of life and mortality in colorectal cancer patients. METHODS: The PubMed, Embase, and Cochrane Central Register of Controlled Trials databases were searched for English language articles published between January 1, 1990 and October 7, 2013. These articles reported results for changes in physical activity and body weight, assessed at pre- to post-diagnosis or at post-diagnosis only. A random effects model was used to analyze pooled quality of life and mortality estimates. RESULTS: Seven eligible studies were identified and analyzed. Increased physical activity was associated with higher overall quality of life scores (N = 3 studies; standardized mean difference (SMD) = 0.74, 95 % confidence interval (CI) = 0.66-0.82), reduced disease-specific mortality risk (hazard ratio (HRpooled) = 0.70, 95 % CI = 0.55-0.85), and reduced overall mortality (HRpooled = 0.75, CI = 0.62-0.87) (N = 2 studies). Weight gain was not associated with disease-specific (HRpooled = 1.02, CI = 0.84-1.20) or overall (HRpooled = 1.03, CI = 0.86-1.19) mortality (N = 3 studies). CONCLUSIONS: Increased physical activity was associated with improved quality of life, a reduced risk of colorectal cancer, and overall mortality rate. Given the paucity of the literature published on this topic, this finding should be interpreted with caution.

Likelihood of early detection of breast cancer in relation to false-positive risk in life-time mammographic screening: population-based cohort study.

BACKGROUND: Women require balanced, high-quality information when making an informed decision on screening benefits and harms before attending biennial mammographic screening. PATIENTS AND METHODS: The cumulative risk of a false-positive recall and/or (small) screen-detected or interval cancer over 13 consecutive screening examinations for women aged 50 from the start of screening were estimated using data from the Nijmegen programme, the Netherlands. RESULTS: Women who underwent 13 successive screens in the period 1975-1976 had a 5.3% cumulative chance of a screen-detected cancer, with a 4.2% risk of at least one false-positive recall. The risk of being diagnosed with interval cancer was 3.7%. Two decades later, these estimates were 6.9%, 7.3% and 2.9%, respectively. The chance of detection of a small, favourable invasive breast cancer, anticipating a normal life-expectancy, rose from 2.3% to 3.7%. Extrapolation to digital screening mammography indicates that the proportion of false-positive results will rise to 16%. CONCLUSION: Dutch women about to participate in the screening programme can be reassured that the chance of false-positive recall in the Netherlands is relatively low. A new screening policy and improved mammography have increased the detection of an early screening carcinoma and lowering the risk of interval carcinoma.

Excess weight among colorectal cancer survivors: target for intervention.

BACKGROUND: Healthy lifestyle might improve outcome among colorectal cancer (CRC) survivors. In this study we investigated the proportion of survivors who meet recommended lifestyle and weight guidelines and compared this to the general population. Factors that predict current behaviour were also assessed. METHOD: A random sample of CRC survivors diagnosed between 1998 and 2007 were surveyed. Percentages of current smokers, alcohol consumers, excess weight and clustering of these variables were calculated. Using logistic regression we assessed demographical and clinical factors that predict current lifestyle and excess weight. RESULTS: We included 1349 (74% response rate) survivors in this study of whom only 8 and 16% of male and female survivors met the recommended lifestyle and body weight. Among male survivors up to 10% had at least two unhealthy lifestyle factors and among women, up to 19%. The proportion of smokers and those who had ever consumed alcohol was lower compared to the general population (13 vs. 31%, 82 vs. 86% respectively), but excess weight (BMI at least 25 kg/m(2)) was more prevalent among survivors (69 vs. 53% respectively). Having received chemotherapy was significantly associated with being overweight (adjusted odd ratio 1.5, 95% confidence interval 1.05-2.3). Younger patients, male gender and survivors of lower socioeconomic status were more likely to show non-compliance to healthy lifestyle recommendations. CONCLUSION: The observed clustering of unhealthy lifestyle warrants interventions targeting multiple behaviours simultaneously. Reducing excess weight should be one of the most important targets of interventions, particularly for males, those who had chemotherapy and survivors of lower socioeconomic status.

Generalisability of the results of the Dutch-Belgian randomised controlled lung cancer CT screening trial (NELSON): does self-selection play a role?

The degree of self-selection in the Dutch-Belgian randomised controlled lung cancer screening trial (NELSON) was determined to assess the generalisability of the study results. 335,441 (mainly) men born in 1928-1953 received a questionnaire. Of the respondents (32%), eligible subjects were invited to participate (19%). Fifty-five percent gave informed consent and was randomised. Background characteristics were compared between male respondents on the first questionnaire (n = 92,802), eligible subjects among them (n = 18,570) and those randomised (n = 10,627) and Statistics Netherlands 2002-2005 (SN) (n = 5289) or GLOBE study-data (Dutch cohort) (n = 696). Initial respondents were less likely to be highly educated (OR(adj) = 0.84; 95% CI: 0.74-0.96) and comprised of significantly less current smokers (OR(adj) = 0.65; 95% CI: 0.61-0.69) compared to the general population. These current smokers smoked more heavily (OR(adj) = 1.23; 95% CI: 1.10-1.37), but for a shorter time-period (respondents: 31, SN: 42 years, p < 0.001). Age, general health, BMI, alcohol use and cancer prevalence were comparable. The randomised population was younger (Age 50-65) (randomised subjects: 85.3%, SN: 72% (p < 0.01)) comprised of more heavy current smokers (OR = 2.08; 95% CI: 1.75-2.44), that smoked for a shorter period of time (randomised subjects: 37, SN_selection: 42 years (p < 0.001)). Both the respondents (32%) of the first questionnaire as well as the randomised population of the NELSON trial appeared to differ slightly on smoking characteristics, but the differences were limited and probably balance each other. Results of the NELSON trial will be roughly applicable to the Dutch and probably other populations that fulfil our selection criteria.

PSA levels and cancer detection rate by centre in the European Randomized Study of Screening for Prostate Cancer.

BACKGROUND: To describe the variation in PSA level by age group and screening round in the ERSPC centres and the variation in cancer detection rates in relation to the underlying prostate cancer incidence. METHODS: Individual data on men invited for the first and second screening rounds according to protocol (excluding early recalls and interval cancers) were obtained from the central database of the ERSPC (cut-off date 31st December 2006). Data were compared between and within centres for the core age group (55-69 at entry). The cancer detection rate (CDR) was compared with the expected background prostate cancer incidence rate in the absence of screening adjusted for the incidence rate in non-attenders and the control arm (IRS). RESULTS: Mean PSA values in the age groups 55-59 years and 65-69 years showed little variation by centre, except for the Dutch centre, where an increase from 1.6 to 1.8 ng/ml and a decline from 2.9 to 2.5ng/ml was observed, respectively. Most tumours were detected at the PSA range 4.0-9.9 ng/ml, with a shift to more cancer detection at 3.0-3.9 ng/ml in the second screening round. There was high variability in the CDR between the centres in both the first (16-46 per 1000) and the second screening rounds (14-50 per 1000). Although the ratio CDR/IRS was less variable, it is somewhat lower in Italy and Switzerland (12 and 14,respectively) and higher in the Netherlands (28), than in most other centres and in Belgium the ratio increased markedly, from 20 to 44 between the first and second rounds. CONCLUSION: There was no clear evidence of a relationship between the underlying incidence and mean PSA levels at screening or the cancer detection rate.

Blinded and uniform causes of death verification in cancer screening: a major influence on the outcome of a prostate cancer screening trial?

BACKGROUND: To assess the agreement between the causes of death assigned by a blinded and uniform review panel of the Rotterdam section of the European Randomised Study of Screening for Prostate Cancer and the official vital statistics and to explore the possible effect of the use of either of these two sources on the outcome of the screening trial. METHODS: A total of 670 deaths amongst men with prostate cancer, reviewed by the causes of death committee (CODC) up to 31st December 2006 were included in this study. The kappa statistics with confidence intervals (CI), sensitivity and specificity of the official statistics were determined, with the CODC considered the gold standard. The rate ratio (RR) and 95% confidence intervals (95% CI) for prostate cancer mortality, official statistics relative to CODC, were calculated following the Mantel-Haenszel procedure. RESULTS: The overall concordance and the kappa between official statistics and the CODC were 90.6% and 0.76 (0.71-0.82), remaining comparable when only the CODC category definitely prostate cancer was applied, with the sensitivity of official statistics increasing from 88.3% to 91.3% and specificity hardly changing (91.3% and 90.5%). High specificity and lower sensitivity is observed in the screening arm, whilst the opposite was seen in the control arm in men aged 55-69 and 70-74 years at entry. Considerable lower false positive rate was seen for both age groups in the screening arm (3.9% and 4.7%) compared to the control arm (8.4% and 14.3%). A statistically significant excess of prostate cancer death was observed for the official statistics in the age group 70-74 years, 1.53 (1.07-2.19), whilst it was not significant for men aged 55-69 at entry, 1.06 (0.83-1.36). CONCLUSION: In the Rotterdam ERSPC section, official statistics tended to overreport prostate cancer as an underlying cause of death, particularly in the age group 70-plus in the control arm, which would overestimate the true effect in favour of screening.

Decreased rates of advanced breast cancer due to mammography screening in The Netherlands.

The effect of the implementation of the Dutch breast cancer screening programme during 1990-1997 on the incidence rates of breast cancer, particularly advanced breast cancer, was analysed according to stage at diagnosis in seven regions, where no screening took place before 1990. The Netherlands Cancer Registry provided detailed data on breast cancer incidence in 1989-1997 by tumour stage, age and region. Annual age-adjusted incidence rates of all breast cancers and advanced cancers, defined as large tumours T2+ with lymph node and/or distant metastases, were compared with rates in 1989. In general, breast cancer incidence rose strongly in the early 1990s, especially in the age category 50-69 years (estimated annual percentage change (EAPC) 4.25; 95% CI 1.70, 6.86). The increase was mainly due to the increase in small T1 cancers and ductal carcinoma in situ. However, in women aged 50-69, advanced cancer incidence rates showed a significant decline by 12.1% in 1997 compared with 1989 (EAPC -2.14, 95% CI -3.47, -0.80), followed by a breast cancer mortality reduction of similar size after approximately 2 years. We confirm that breast cancer screening initially leads to a temporary strong increase in the breast cancer incidence, which is followed by a significant decrease in advanced diseases in the women invited for screening. It is evident that breast cancer screening contributes to a reduction in advanced breast cancers and breast cancer mortality.

Low all-cause mortality in the volunteer-based Rotterdam section of the European randomised study of screening for prostate cancer: self-selection bias?

OBJECTIVES: The likelihood of self-selection bias in a cohort of men that entered the volunteer-based randomised prostate cancer screening trial was assessed. In addition, the accuracy of the randomisation was evaluated by comparison amongst the trial arms. SETTING: The Rotterdam section of the European Randomised Study of Screening for Prostate Cancer (ERSPC). Participants were recruited from population registries and randomised after receipt of written informed consent (49% participation rate). METHODS: Data from 37,614 men who entered the Rotterdam trial between June 1994 and July 1999 were linked to the Causes of Death Registry of Statistics Netherlands. For the assessment of self-selection bias, mortality in the trial cohort and the area of Rotterdam was compared by calculating standardised mortality ratios (SMRs, 95% confidence interval [CI]). Comparisons between the screening and the control arm were made by means of relative risk (RR). RESULTS: There were a total of 1661 deaths (4.4%) in the trial cohort, during an average follow-up time of 2.8 years. The observed number of deaths in the two arms combined was lower than expected (SMR 86.7%, 95% CI 81.6-92.1), which was reflected in the major cause of death categories, especially in all malignant neoplasms. No difference was observed in the all-cause mortality rate among the screening and control arm, aged 55-69 years at entry (RR 1.00, 95% CI 0.89-1.12), nor when all causes, excluding prostate cancer mortality, were considered. CONCLUSIONS: The preliminary results show that the screening and the control arm were comparable, but men recruited for the trial seemed healthier than men in the target population.

Increased risk of postpartum depressive symptoms is associated with slower normalization after pregnancy of the functional docosahexaenoic acid status.

Observational studies suggest an association between a low docosahexaenoic acid (DHA, 22:6n-3) status after pregnancy and the occurrence of postpartum depression. However, a comparison of the actual biochemical plasma DHA status among women with and without postpartum depression has not been reported yet. The contents of DHA and of its status indicator n-6 docosapentaenoic acid (n-6DPA, 22:5n-6) were measured in the plasma phospholipids of 112 women at delivery and 32 weeks postpartum. At this latter time point, the Edinburgh Postnatal Depression Scale (EPDS) questionnaire was completed to measure postpartum depression retrospectively. The EPDS cutoff score of 10 was used to define 'possibly depressed' (EPDS score > or =10) and non-depressed women (EPDS score <10). Odds ratios (OR) were calculated using a multiple logistic regression analysis with the EPDS cutoff score as dependent and fatty acid concentrations and ratio's as explanatory variables, while controlling for different covariables. The results demonstrated that the postpartum increase of the functional DHA status, expressed as the ratio DHA/n-6DPA, was significantly lower in the 'possibly depressed' group compared to the non-depressed group (2.34+/-5.56 versus 4.86+/-5.41, respectively; OR=0.88, P=0.03). Lactating women were not more predisposed than non-lactating women were to develop depressive symptoms. From this observation it seems that the availability of DHA in the postpartum period is less in women developing depressive symptoms. Although further studies are needed for confirmation, increasing the dietary DHA intake during pregnancy and postpartum, seems prudent.

Comparison of the peripartum and postpartum phospholipid polyunsaturated fatty acid profiles of lactating and nonlactating women.

BACKGROUND: Pregnancy is associated with increased absolute amounts of docosahexaenoic acid (DHA; 22:6n-3) in plasma phospholipids. Expressed as a proportion of total fatty acids, DHA declines slightly in late pregnancy but little information is available on the normalization of DHA postpartum, which may be different in lactating and nonlactating women. OBJECTIVE: The aim was to investigate maternal plasma and erythrocyte long-chain polyunsaturated fatty acids (long-chain polyenes; LCPs) postpartum, particularly DHA, in relation to lactation and dietary LCP intake. DESIGN: Healthy pregnant women who intended to breast-feed or exclusively bottle-feed their infants were studied at 36-37 wk of pregnancy. Blood samples were collected at entry, after parturition on days 2 and 5, and 1, 2, 4, 8, 16, 32, and 64 wk postpartum. Fatty acid profiles were analyzed in plasma and erythrocyte phospholipids. Dietary intakes were assessed 4 and 32 wk postpartum with a validated food-frequency questionnaire. RESULTS: After delivery, the percentages of plasma linoleic, arachidonic, eicosapentaenoic, and docosapentaenoic acids increased over time, whereas the percentage of docosapentaenoic acid decreased; the patterns of change did not differ significantly between the lactating and nonlactating groups. The percentage of DHA in plasma and erythrocyte phospholipid fatty acids declined significantly in the 2 groups, more so in the lactating women, and was enhanced when the lactation period was extended. Despite the apparent higher dietary intake of essential fatty acids in the lactating group at week 4, it was not significantly different from that of the nonlactating group. CONCLUSION: Normalization of maternal plasma and erythrocyte phospholipid n-3 LCPs differs significantly between lactating and nonlactating women postpartum but that of n-6 LCPs does not.

Leptin and phospholipid-esterified docosahexaenoic acid concentrations in plasma of women: observations during pregnancy and lactation.

BACKGROUND: The n-3 fatty acid status changes during pregnancy and lactation. Plasma leptin concentrations and gene expression have been related to n-3 fatty acids. OBJECTIVE: To investigate the relation between plasma leptin concentration and the docosahexaenoic acid (22:6n-3) content of plasma phospholipids during early pregnancy and the postpartum period. DESIGN: Leptin (radioimmunoassay) and the phospholipid fatty acid profile (capillary gas-liquid chromatography) were measured in plasma of women during two independent longitudinal observational studies. Dietary intake of n-3 fatty acids was also determined. RESULTS: Within the first 10 weeks after the last menstrual period, an almost parallel increase in leptin concentration and the 22:6n-3 content (mg/l and % wt/wt) of plasma phospholipids was seen (study 1, n = 21). During the postpartum period (study 2, n = 57), leptin levels decreased quickly, preceding the changes in 22:6n-3 concentrations. During both studies, leptin concentrations did not consistently relate to dietary intake of n-3 fatty acids or to 22:6n-3 concentrations in plasma phospholipids. Before and during early pregnancy (study 1), significant positive associations between leptin levels and the total amount of phospholipid-associated fatty acids were found. No such association was seen during late pregnancy or the postpartum period (study 2). The postpartum decrease in leptin levels did not differ between lactating and non-lactating women. CONCLUSIONS: Not the 22:6n-3 content, but the total amount of phospholipid-associated fatty acids was related to plasma leptin concentration, before and during early pregnancy but not during late pregnancy and the postpartum period.

Changes in the maternal essential fatty acid profile during early pregnancy and the relation of the profile to diet.

BACKGROUND: Although the pattern of the essential fatty acids (EFAs) changes considerably from week 10 of pregnancy to term, no information is available on changes in EFA concentrations in the early stages of pregnancy. OBJECTIVE: The main objectives were to assess the EFA status, particularly that of 22:6n-3, in women during the first 10 wk of pregnancy and to investigate the relation of EFA status to dietary EFA intake during this period. DESIGN: Healthy women (n = 24) planning to become pregnant were recruited. The fatty acid composition of plasma and erythrocyte phospholipids was determined before and at weeks 4, 6, 8, and 10 of pregnancy. Food intake was assessed at entry into the study and at week 10 of pregnancy by using food-frequency questionnaires. RESULTS: A small but nonsignificant increase in dietary intake of 22:6n-3 was found. The plasma phospholipid content of 22:6n-3 (% by wt) increased continuously during the first 10 wk of pregnancy. At week 10 of pregnancy, the plasma percentages of 16:0, 20:3n-6, and 20:4n-6 had increased significantly, whereas the percentages of the 18-24-carbon saturated fatty acids, 18:2n-6, and the ratio of n-6 to n-3 fatty acids had dropped significantly. The composition of erythrocyte phospholipids showed changes similar to those observed in plasma. CONCLUSIONS: Maternal plasma and erythrocyte phospholipid 22:6n-3 concentrations start to increase in very early pregnancy, which cannot be explained by changes in dietary intake alone. This rise probably represents early maternal adaptations to meet the requirements of highly proliferating and differentiating tissues at this stage of fetal development.

The effect of supplementation with docosahexaenoic and arachidonic acid derived from single cell oils on plasma and erythrocyte fatty acids of pregnant women in the second trimester.

This study was performed to investigate whether supplementation of docosahexaenoic acid (DHA) and arachidonic acid (AA) to pregnant women would enhance their DHA levels, both in plasma and in erythrocyte phospholipids, without reducing the content of n-6 long-chain ployenes (LCP) usually seen when DHA is supplemented alone. Healthy pregnant women, in the second trimester, were randomly assigned to either the control group (n=12) or the intervention group (n=12). The control group received no supplements and the intervention group received daily during 4 weeks encapsulated algae-derived DHA oil (0.57 g DHA/day) and fungal-derived AA oil (0.26 g AA/day). The fatty acid compositions of plasma and erythrocyte phospholipids were determined in weekly-collected blood samples. DHA and n-6 LCP levels of the control group were unchanged after 4 weeks. Compared to the control group, DHA levels in plasma an erythrocytes of the intervention group increased significantly. No significant reductions were found in the levels of AA and total n-6 LCP. The supplement proved to be effective in increasing the DHA levels in both plasma and erythrocyte without a concomitant decline of the n-6 LCP.

Microprocessor controlled movement of liquid gastric content using sequential neural electrical stimulation.

BACKGROUND: Gastric electrical stimulation has been attempted for several years with little success. AIMS: To determine whether movement of liquid gastric content could be achieved using microprocessor controlled sequential electrical stimulation. METHODS: Eight anaesthetised dogs underwent laparotomy and implantation of four sets of bipolar stainless steel wire electrodes. Each set consisted of two to six electrodes (10x0.25 mm, 3 cm apart) implanted circumferentially. The stomach was filled with water and the process of gastric emptying was monitored. Artificial contractions were produced using microprocessor controlled phase locked bipolar four second trains of 50 Hz, 14 V (peak to peak) rectangular voltage. In four of the dogs four force transducers were implanted close to each circumferential electrode set. In one gastroparetic patient the effect of direct electrical stimulation was determined at laparotomy. RESULTS: Using the above stimulating parameters circumferential gastric contractions were produced which were artificially propagated distally by phase locking the stimulating voltage. Averaged stimulated gastric emptying times were significantly shorter than spontaneus emptying times (t1/2 6.7 (3.0) versus 25.3 (12.9) minutes, p<0.01). Gastric electrical stimulation of the gastroparetic patient at operation produced circumferential contractions. CONCLUSIONS: Microprocessor controlled electrical stimulation produced artificial peristalsis and notably accelerated the movement of liquid gastric content.

Reliability of percent distribution of power of the electrogastrogram in recognizing gastric electrical uncoupling.

The aim of this study was to examine the reliability of percent distribution of electrogastrographic (EGG) power in recognizing gastric electrical uncoupling. Sixteen anaesthetized dogs underwent laparotomy and implantation of six pairs of stainless-steel wire electrodes. Distal stomach was measured and three sections with approximately equal lengths were defined. Two pairs of electrodes were implanted in each section. Eight-channel EGG was also recorded. Three separate half-hour recordings were made: in the basal state; after a full circumferential separation of the distal antral section from the rest; after a second circumferential cut completely separating the middle from the proximal sections. EGG digital power spectra were split into three frequency ranges and dynamics of percent distribution of power was statistically examined. After the first cut, changes in the percent distribution of EGG power in the normal range were not significant (p = 0.2). Significant changes in the low range were noted (p < 0.05) and changes in the high range were borderline nonsignificant (p = 0.056). After the second cut, changes in percent distribution in the normal and the high range became significant (p < 0.01) while changes in the low range were insignificant (p = 0.075). Severe uncoupling was reflected in EGG by significant changes in the high-frequency range without internal tachygastria necessarily being present.

Electrogastrography can recognize gastric electrical uncoupling in dogs.

BACKGROUND & AIMS: Electrical uncoupling is the lack of electrical synchronization in different parts of the stomach. The ability of electrogastrography (EGG) to recognize gastric electrical uncoupling has not been adequately studied. The aim of this study was to determine the impact on EGG of surgically introduced gastric uncoupling in anesthesized dogs. METHODS: Six pairs of bipolar electrodes were inserted into the antral gastric wall of 16 anesthetized dogs at laparotomy. Eight-channel bipolar cutaneous EGGs were simultaneously recorded. Three separate half-hour recordings were made from each dog in the basal state and after each of two circumferential cuts of all gastric muscle. The stomach was divided into three equally sized areas, each with an electrode pair in its anterior and posterior walls. Gastric electrical activity was assessed visually. EGG was digitized and processed by computer. RESULTS: Criteria for EGG normality were defined from 9 dogs with normal gastric electrical activity. After the first antral cut, internal recordings from the area below the division were at a lower frequency and often irregular. The second cut produced three different frequencies. Suggested criteria for normality allowed correct recognition of 93% of all severely abnormal records. Records with mild gastric electrical abnormalities were recognized with a sensitivity of 74%. CONCLUSIONS: EGG can recognize severe electrical uncoupling.

Maternal and neonatal essential fatty acid status in phospholipids: an international comparative study.

OBJECTIVE: To investigate whether the steady decline in the maternal essential fatty acids (EFA) status during pregnancy observed in Dutch pregnant women is a local or general phenomenon. DESIGN: The EFA status was measured during uncomplicated, singleton pregnancy of healthy women from the Netherlands, Hungary, Finland, England and Ecuador. In addition, the EFA status of their neonates were measured at birth. Fatty acid profiles were analyzed in phospholipids isolated from maternal plasma and from umbilical plasma and cord vessel walls. RESULTS: Considerable differences between these centers were observed in the maternal EFA levels and EFA status indexes. However, the change in the absolute as well as relative amounts of the EFAs followed a similar course in the five populations during pregnancy. The neonatal EFA profiles reflected the differences found in maternal plasma during pregnancy and shortly after delivery. Comparable correlations were found, particularly, between the neonatal and the maternal n-3 fatty acids in the participating groups. CONCLUSIONS: It seems that the reduction in maternal EFA status during pregnancy is a general phenomenon, and is largely independent of differences in dietary habits and ethnic origin. Since the lowest values for certain maternal EFAs in a given country were significantly higher than the highest value of these EFAs throughout pregnancy in other countries, the functional implications of the pregnancy-associated reduction in the maternal EFA status for the fetal and neonatal development is not obvious and needs to be further elucidated.

Effects of storage on venous and capillary blood samples: the influence of deferoxamine and butylated hydroxytoluene on the fatty acid alterations in red blood cell phospholipids.

Fatty acid concentrations in plasma and red blood cell phospholipids isolated from paired venous and capillary blood samples were compared and the effect of storage at -20 degrees C was evaluated as well. Plasma fatty acid profiles from venous and capillary blood were found to be comparable and not affected by up to four weeks of storage, while fatty acid profiles of venous and capillary red blood cells were no longer comparable after four weeks. Substantial losses of long-chain polyunsaturated fatty acids were observed in capillary red blood cells. To investigate whether the observed long-chain polyunsaturated fatty acids loss could be prevented, capillary red blood samples were stored for up to one year at -50 degrees C in the presence of the iron-binding agent deferoxamine or the free radical scavenger butylated hydroxytoluene. Both compounds protected the long-chain polyunsaturated fatty acids. Similarly, storage of red blood cell lipid extracts at -50 degrees C for up to one year was not associated with reduced levels of long-chain polyunsaturated fatty acids. In conclusion, the lipid loss from capillary red blood cells can be reduced for at least one year during storage at -50 degrees C with prior addition of either a metal chelating compound or a free radical scavenger, or by preparing lipid extracts of the samples within one week of blood collection.