Serum Concentrations of 25-Hydroxyvitamin D and Depression in a General Middle-Aged to Elderly Population in Finland.

OBJECTIVES: Low concentrations of serum 25-hydroxyvitamin D [25(OH)D] have been postulated to associate with an increased prevalence of depression. As there are a limited number of publications on this issue, we examined the association between serum 25(OH)D and depression in a general middle-aged or older population. DESIGN: A population-based cross-sectional study. SETTING AND PARTICIPANTS: A total of 1602 men and women from the population-based Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) in Eastern Finland, aged 53-73 y in 1998-2001, were analysed. MEASUREMENTS: Depressive symptoms were assessed with the DSM-III depression scale, and those individuals who had scores over 4 (range 0-12) or had reported undergoing current antidepressant therapy, were considered as suffering from depression. Associations were estimated in serum 25(OH)D tertiles using logistic regression. RESULTS: Among the participants, 183 subjects (11.4%) were considered to have depression. The mean age of the subjects was 62.6 years (SD 6.4, range 53.4-73.8 years). The mean serum 25(OH)D concentration was 43.8 nmol/L (SD 17.7, range 8.5-112.8 nmol/L), concentrations <50 nmol/L were observed in 65.0% of the subjects, and only 5.0% displayed concentrations ≥75 nmol/L. After multivariable adjustments, the odds ratios for having depression in the tertiles (from highest to the lowest) of serum 25(OH)D were 1, 1.35 (95 % CI: 0.87, 2.09) and 1.64 (95 % CI: 1.03, 2.59), P for trend=0.036. CONCLUSION: These findings indicate that a lower concentration of serum 25(OH)D is associated with a higher prevalence of depression in an elderly general population.

Omega-6 polyunsaturated fatty acids, serum zinc, delta-5- and delta-6-desaturase activities and incident metabolic syndrome.

BACKGROUND: The associations of n-6 polyunsaturated fatty acids (PUFA) with metabolic syndrome have been poorly explored. We investigated the associations of the serum n-6 PUFA and the activities of enzymes involved in the PUFA metabolism, delta-5-desaturase (D5D) and delta-6-desaturase (D6D) with risk of incident metabolic syndrome. We also investigated whether zinc, a cofactor for these enzymes, modifies these associations. METHODS: A prospective follow-up study was conducted on 661 men who were aged 42-60 years old at baseline in 1984-1989 and who were re-examined in 1998-2001. RESULTS: Men in the highest versus the lowest serum total omega-6 PUFA tertile had a 70% lower multivariate-adjusted risk of incident metabolic syndrome [odds ratio (OR) = 0.30; 95% confidence interval (CI) = 0.18-0.51, Ptrend < 0.001]. Inverse associations were also observed for linoleic acid, arachidonic acid and D5D activity. By contrast, men in the highest tertile of D6D activity had an 84% higher risk (OR = 1.84; 95% CI = 1.15-2.94, Ptrend = 0.008). Similar associations were observed with many of the metabolic syndrome components at the re-examinations. Most associations were attenuated after adjustment for body mass index. Finally, the associations of D6D and LA were stronger among those with a higher serum zinc concentration. CONCLUSIONS: Higher serum total n-6 PUFA, linoleic acid and arachidonic acid concentrations and D5D activity were associated with a lower risk of developing metabolic syndrome and higher D6D activity was associated with a higher risk. The role of zinc also needs to be investigated in other populations.

Hepatitis C and risk of coronary atherosclerosis - A systematic review.

BACKGROUND: Observational studies on the association of chronic hepatitis C with coronary atherosclerosis have shown varying results and previous related reviews have been inconclusive. By careful outcome classification and further data syntheses, we aimed to clarify current evidence on the association between hepatitis C infection and coronary atherosclerosis. METHODS: Through systematic searches of PubMed and Scopus, related published observational studies were identified. These were narrowed by review of abstract, full review and quality assessment to yield eligible studies. These were used in qualitative and quantitative syntheses. RESULTS: The initial search identified 274 unique publications, which were narrowed to 15 by means of preliminary reviews, and narrowed further to 10 by quality assessment. The endpoints assessed varied, representing different attributes of the disease. The 10 studies were used in the subsequent meta-analyses. The risk of a person with chronic hepatitis C developing coronary atherosclerosis is about triple the risk in uninfected persons (OR = 3.06, 95% CI = 1.99-4.72). Coronary atherosclerosis in persons with chronic hepatitis C is also more severe. The pooled risk of coronary atherosclerosis-related events in persons with chronic hepatitis C was null (OR = 1.10 95% CI = 0.80-1.52). CONCLUSION: The current evidence indicates that hepatitis C virus or factors associated with HCV infection are apparently associated with increased risk of occurrence of coronary atherosclerosis and probably, increased severity of coronary atherosclerosis. Evidence of association with coronary atherosclerosis-related events is yet indeterminate.

Association between serum long-chain omega-3 polyunsaturated fatty acids and cognitive performance in elderly men and women: The Kuopio Ischaemic Heart Disease Risk Factor Study.

BACKGROUND/OBJECTIVES: Fish intake and the long-chain omega-3 polyunsaturated fatty acids (PUFAs) in fish have been suggested to lower the risk of cognitive decline. We assessed whether serum long-chain omega-3 PUFAs eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) are associated with performance on neuropsychological tests in an older population and whether exposure to methylmercury, mainly from fish, or apolipoprotein-E4 (Apo-E4) phenotype can modify the associations. SUBJECTS/METHODS: A total of 768 participants from the population-based Kuopio Ischaemic Heart Disease Risk Factor Study were included. Cognitive function was measured using five neuropsychological tests: the Trail Making Test, the Verbal Fluency Test, the Selective Reminding Test, the Visual Reproduction Test and the Mini Mental State Exam. Multivariate-adjusted analysis of covariance and linear regression were used to analyze the cross-sectional associations. RESULTS: We found statistically significant associations between serum EPA+DPA+DHA and better performance in the Trail Making Test and the Verbal Fluency Test. The individual associations with EPA and DHA were similar with the findings with EPA+DPA+DHA, although the associations with DHA were stronger. No associations were observed with serum DPA. Pubic hair mercury content was associated only with a worse performance in the Trail Making Test, and mercury had only little impact on the associations between the serum PUFAs and cognitive performance. Apo-E4 phenotype did not modify the associations with PUFAs or mercury. CONCLUSIONS: Higher serum long-chain omega-3 PUFA concentrations were associated with better performance on neuropsychological tests of frontal lobe functioning in older men and women. Mercury exposure or Apo-E4 phenotype had little impact on cognitive performance.

Associations of serum n-3 and n-6 polyunsaturated fatty acids with plasma natriuretic peptides.

BACKGROUND/OBJECTIVES: The n-3 and n-6 polyunsaturated fatty acids (PUFAs) have been associated with lower risk of cardiovascular disease (CVD), but little is known about their association with natriuretic peptides (NPs), a marker for CVD risk. The aim of this study was to investigate the association of serum n-3 and n-6 PUFAs with NPs. SUBJECTS/METHODS: A cross-sectional analysis of the association between serum n-3 and n-6 PUFAs with plasma N-terminal atrial (NT-proANP) and brain (NT-proBNP) NPs in a population-based sample of 985 men aged 46-65 years from Eastern Finland. RESULTS: After adjustment for age and examination year, only serum n-6 PUFA arachidonic acid (ARA) was inversely associated with NT-proANP (P-trend across quartiles=0.02), but further adjustments for conventional risk factors (body mass index, smoking, alcohol intake, systolic blood pressure, low-density lipoprotein cholesterol and history of CVD) attenuated the association (P-trend=0.10). The associations with the other PUFAs were not statistically significant. Among the PUFAs, only serum n-3 PUFA docosapentaenoic acid (DPA; P-trend=0.03) and ARA (P-trend=0.02) had inverse associations with NT-proBNP after adjustment for age and examination years. The associations were again attenuated after further adjustments but remained statistically significant for DPA (P-trend=0.05). Our results also suggested that the inverse associations may be more evident among those using beta-blockers. CONCLUSIONS: Our study suggests little overall impact of serum n-3 or n-6 PUFAs on plasma NPs.

Association of adipokines and estradiol with bone and carotid calcifications in postmenopausal women.

OBJECTIVES: Carotid artery calcifications (CAC) and high carotid artery intima-media thickness (cIMT) are associated with low bone mineral density (BMD) by unknown mechanisms in postmenopausal women. Leptin, adiponectin and estradiol may mediate these associations. Our aim was to study the relationships of the aforementioned factors to bone health (BMD) and carotid atherosclerosis (CAC and cIMT). METHOD: Participants (n = 290, mean age 73.6 years) for this cross-sectional OSTPRE-BBA study (Kuopio Osteoporosis Risk Factor and Prevention - Bone, Brain and Atherosclerosis) were randomly selected from the OSTPRE cohort in 2009. Femoral neck and total body BMDs, trunk and total body fat mass were measured with dual-energy X-ray absorptiometry, and cIMT (mm) and CAC (no/yes) were measured with B-type ultrasound. Free estradiol, adiponectin and leptin were measured from serum samples. RESULTS: Circulating estradiol levels were associated with leptin (ß = 0.131, p < 0.001), but not with adiponectin (p > 0.05), when adjusted for total body fat mass. There were no associations between estradiol tertiles and BMDs, or with cIMT or CAC. Adiponectin levels were inversely associated with femoral neck BMD (p = 0.019, ß = -0.138) and total body BMD (p = 0.009, ß = -0.142), adjusted for total body fat mass, age, current smoking and estradiol, but showed no relationship with CAC or cIMT. Leptin levels were not associated with BMDs or cIMT; but the odds ratio was 1.5 between the CAC and leptin quartiles (p = 0.014), adjusted for total body fat mass, age, statin use and calcium intake. CONCLUSION: The adipokines are associated with vascular calcification and low BMD. Moreover, estradiol was not independently associated with BMD or CAC.

Serum long-chain omega-3 polyunsaturated Fatty acids and future blood pressure in an ageing population.

OBJECTIVES: To investigate the associations of serum long-chain omega-3 polyunsaturated fatty acids (PUFA) and hair mercury with future blood pressure in an ageing population. DESIGN: Prospective study with baseline measurements in 1998-2001 and follow-up measurements in 2005-2008. The linear relationships (ß) of baseline serum fatty acids and hair mercury with future systolic and diastolic blood pressure and pulse pressure were analyzed with multiple linear regression models, using log-transformed values. PARTICIPANTS: 181 men and 200 women aged 53-73 y from the Kuopio Ischemic Heart Disease Risk Factor Study (KIHD) population in Eastern Finland, who were free of cardiovascular disease, diabetes or hypertension at baseline. MEASUREMENTS: Total serum esterified and nonesterified fatty acids and pubic hair mercury were used as markers for exposure. Anthropometric and other lifestyle and health-related data were collected. RESULTS: The mean serum concentrations were 1.67% (SD 0.92) for eicosapentaenoic acid (EPA), 0.79% (SD 0.16) for docosapentaenoic acid (DPA) and 2.78 (SD 0.92) for docosahexaenoic acid (DHA), of all serum fatty acids. The mean hair mercury concentration was 1.5 µg/g (SD 1.6). We did not find statistically significant associations between the baseline serum long-chain omega-3 PUFA concentrations or hair mercury content and future blood pressure. Hair mercury did not modify the associations with the long-chain omega-3 PUFAs, either. CONCLUSIONS: Higher serum long-chain omega-3 PUFA concentration, a biomarker of fish or fish oil consumption, may not have an impact on future blood pressure in an ageing population.

Association of serum n-3 polyunsaturated fatty acids with C-reactive protein in men.

BACKGROUND/OBJECTIVES: N-3 polyunsaturated fatty acids (PUFAs) have been associated with reduced inflammation. We tested the hypothesis that high serum concentrations of the n-3 PUFAs are associated with lower serum C-reactive protein (CRP) concentrations in healthy middle-aged Finnish men. We also examined whether exposure to mercury, an environmental contaminant in fish, which is also a major source of long-chain n-3 PUFA, was associated with CRP. SUBJECTS/METHODS: Data from the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study were analyzed cross-sectionally to determine the associations between serum n-3 PUFAs, hair mercury and serum CRP in 1395 healthy men, aged 42-60 years. Linear regression analyses were performed to analyze the associations. RESULTS: In the multivariate models, the mean serum CRP in quartiles of serum total n-3 PUFA concentration was 1.23, 1.27, 1.18 and 1.08 mg/l, P for trend = 0.01. Statistically significant inverse associations were also observed with the total serum long-chain n-3 PUFA concentration and with the individual long-chain n-3 PUFAs docosapentaenoic acid and docosahexaenoic acid, but not with eicosapentaenoic acid or with the intermediate-chain n-3 PUFA alpha-linolenic acid. Hair methylmercury content was not associated with serum CRP levels and it did not modify the associations between serum n-3 PUFAs and CRP either. CONCLUSIONS: Serum n-3 PUFAs and especially the long-chain n-3 PUFA concentration, a marker of fish or fish oil consumption, were inversely associated with serum CRP in men. Exposure to mercury was not associated with serum CRP.

Two-minute heart rate recovery after cycle ergometer exercise and all-cause mortality in middle-aged men.

BACKGROUND: A slow heart rate recovery (HRR) after an exercise test is associated with an increased risk of all-cause mortality in asymptomatic individuals, but the data regarding additional prognostic information provided by HRR beyond other exercise test variables are inconsistent. We investigated the prognostic significance of HRR for premature death, particularly in relation to other exercise test variables. METHODS: The study subjects were a representative population-based sample of 1102 men (42-61 years of age) without cardiovascular disease, cancer or diabetes. HRR was defined as the difference between maximal HR and HR 2 min after a maximal symptom-limited exercise test using a cycle ergometer. The association between HRR and premature mortality was examined with Cox regression models. RESULTS: During an average follow-up of 18 years, 238 deaths occurred. HRR was an independent predictor of death [for a decrease of 12 beats min(-1) , relative risk (RR) 1.16, 95% CI 1.02-1.33, P = 0.02] after adjustment for age and established risk factors. When added in a Cox model with chronotropic response (decrease of 12 beats min(-1) , RR 1.09, 95% CI 0.93-1.27, P = 0.26) or cardiorespiratory fitness (decrease of 12 beats min(-1) , RR 1.12, 95% CI 0.98-1.30, P = 0.08), the association between a slow HRR and an increased risk of death was clearly weaker. CONCLUSION: A slow 2-min HRR after a cycle ergometer exercise test was an independent predictor of death in healthy middle-aged men after accounting for demographic and clinical characteristics. However, it was no longer predictive after accounting for chronotropic response and exercise capacity.

Glycemic index, glycemic load, and the risk of acute myocardial infarction in Finnish men: the Kuopio Ischaemic Heart Disease Risk Factor Study.

BACKGROUND AND AIM: The role of dietary glycemic index (GI) and glycemic load (GL) in coronary heart disease (CHD) is unclear. Our aim was to study the association between the dietary GI and GL and the risk of acute myocardial infarction (AMI). METHODS AND RESULTS: The study population consisted of 1981 Finnish men from the prospective population-based Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study, aged 42-60 years and free of CHD at baseline. During an average follow-up time of 16.1 years, 376 new AMI events occurred. In multivariable-adjusted Cox proportional hazards models, the relative risk (RR) for AMI in the highest quartile of GI was 1.25 (95% CI: 0.92-1.69; P for trend=0.08) and for GL 1.11 (95% CI: 0.79-1.57; P for trend=0.21) when compared with the lowest quartile. For overweight (BMI ≥ 27.5 kg/m²) men, the multivariable-adjusted RR for AMI in the highest compared to the lowest tertile of GI and GL were 1.58 (95% CI: 1.03-2.43; P for trend=0.04, P for interaction=0.01) and 2.05 (95% CI: 1.30-3.23; P for trend=0.002, P for interaction=0.002), respectively. For physically less active men; energy expenditure for leisure-time physical activity < 50 kcal/d, the RR for AMI was 1.72 (95% CI: 1.07-2.76; P for trend=0.04, P for interaction 0.80) with higher GL. CONCLUSIONS: Our results suggest that both high dietary GI and GL are associated with increased risk of AMI among overweight and GL possibly among less physically active men.

Systematically missing confounders in individual participant data meta-analysis of observational cohort studies.

One difficulty in performing meta-analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an exposure and disease either are restricted to cohorts with full confounder information, or use all cohorts but do not fully adjust for confounding. We propose using a bivariate random-effects meta-analysis model to use information from all available cohorts while still adjusting for all the potential confounders. Our method uses both the fully adjusted and the partially adjusted estimated effects in the cohorts with full confounder information, together with an estimate of their within-cohort correlation. The method is applied to estimate the association between fibrinogen level and coronary heart disease incidence using data from 154,012 participants in 31 cohorts

C-reactive protein and the development of the metabolic syndrome and diabetes in middle-aged men.

AIMS/HYPOTHESIS: Low-grade inflammation has been implicated in the development of Type 2 diabetes and cardiovascular disease, but its role in the pathogenesis of the metabolic syndrome is unclear. We investigated the association between C-reactive protein (CRP) levels and the development of the metabolic syndrome and diabetes in men. METHODS: Serum CRP concentrations and factors related to insulin resistance were determined in middle-aged Finnish men who participated in a population-based cohort study and were free of diabetes at baseline. RESULTS: At the 11-year follow-up, 143 of 680 men had developed the metabolic syndrome as defined by the National Cholesterol Education Program (NCEP) and 103 of 598 men had developed the metabolic syndrome as defined by the World Health Organization (WHO). Our analyses excluded men with the metabolic syndrome by the respective definition at baseline. In all, 78 of 762 men developed diabetes over the same period. Men with CRP concentrations > or =3 mg/l had a several-fold higher age-adjusted risk of developing the metabolic syndrome (NCEP definition: odds ratio [OR]=3.2, 95% CI 1.9-5.5; WHO definition: OR=3.4, 95% CI 2.0-6.1) or diabetes (OR=4.1, 95% CI 2.1-8.0) than men whose CRP levels were <1.0 mg/l. Even after further adjustment for potentially confounding lifestyle factors and factors related to insulin resistance, the risk of diabetes (OR=2.3, 95% CI 1.0-5.1) was still increased in men with CRP concentrations > or =3 mg/l, but the association with the metabolic syndrome was no longer significant. CONCLUSIONS/INTERPRETATION: Low-grade inflammation may increase the risk of the metabolic syndrome and diabetes in middle-aged men, but some of the risk is mediated through obesity and factors related to insulin resistance.

Association of exercise-induced, silent ST-segment depression with the risk of stroke and cardiovascular diseases in men.

BACKGROUND AND PURPOSE: There are few if any data on the prognostic importance of silent myocardial ischemia during exercise with regard to the risk of stroke and cardiovascular diseases (CVDs) among asymptomatic men. In this prospective study, we investigated the relation of silent myocardial ischemia and the risk of stroke and CVD death in men with and without conventional risk factors. METHODS: The study sample included 1726 middle-aged men with no history of stroke, coronary heart disease, or atrial fibrillation at baseline. Silent myocardial ischemia was defined as a horizontal or downsloping ST-segment depression (>or=1 mm) during exercise electrocardiography. A total of 86 CVD-related deaths and 78 strokes occurred during an average follow-up of 10 years. RESULTS: Men with silent ischemia during exercise had a 3.5-fold increased risk of CVD death and a 2.2-fold increased risk of stroke compared with men without silent ischemia, after adjusting for conventional risk factors. Silent ischemia during exercise was associated with a 3.8-fold (95% confidence interval [CI], 1.5 to 9.5) increased risk for CVD in smokers, a 3.9-fold (95% CI, 2.1 to 7.3) increased risk in hypercholesterolemic subjects, a 3.6-fold (95% CI, 1.9 to 6.8) increased risk in the hypertensives, and 3.8-fold (95% CI, 2.0 to 7.1) increased risk in overweight men. The respective relative risks for stroke were 3.8 (95% CI, 1.1 to 12.5), 3.5 (95% CI, 1.7 to 7.4), 3.4 (95% CI, 1.6 to 7.1), and 2.9 (95% CI, 1.4 to 6.1). CONCLUSIONS: Exercise-induced silent myocardial ischemia is an important indicator of increased risk of stroke and CVD in men with other risk factors, such as smoking, hypercholesterolemia, hypertension, and being overweight.