Relation of serum BDNF to major depression and exploration of mechanistic roles of serum BDNF in a study of vitamin D3 and omega-3 supplements for late-life depression prevention.

This study: 1) examined cross-sectional and longitudinal relations of serum brain-derived neurotrophic factor (BDNF) to late-life depression (LLD); 2) tested effects of vitamin D3 and omega-3s on change in BDNF; 3) explored modifying or mediating roles of BDNF on effects of vitamin D3 and omega-3s for LLD. We selected 400 adults from a completed trial of vitamin D3 and omega-3 supplements for LLD prevention. BDNF was measured using an enzyme-linked immunosorbent assay. We administered semi-structured diagnostic interviews and Patient Health Questionnaire [PHQ]-9 to ascertain outcomes at baseline (depression caseness vs. non-caseness; PHQ-9) and at 2-year follow-up among baseline non-depressed individuals (incident vs. no incident MDD; change in PHQ-9). At baseline, while there were no significant differences in mean serum BDNF comparing depression cases and non-cases, being in the lowest vs. highest serum BDNF quartile was significantly associated with worse depressive symptoms. There were no significant longitudinal associations between serum BDNF and LLD. Neither supplement significantly affected change in BDNF; serum BDNF did not appear to modify or mediate treatment effects on LLD. In conclusion, we observed significant cross-sectional but not longitudinal associations between serum BDNF levels and LLD. Vitamin D3 or omega-3s did not alter serum BDNF over 2 years.

Effects of Vitamin D Supplementation on C-peptide and 25-hydroxyvitamin D Concentrations at 3 and 6 Months.

The link between African-Americans' disproportionate rates of diabetes, obesity and vitamin D deficiency may be marked by C-peptide as an indicator of insulin secretion. We hypothesize that vitamin D supplementation will increase C-peptide, a marker of insulin secretion. During 3 winters from 2007-2010, 328 healthy African-Americans (median age, 51 years) living in Boston, MA were randomized into a 4-arm, double-blind trial for 3 months of placebo, 1000, 2000, or 4000 IU of vitamin D3. The differences in non-fasting C-peptide between baseline and 3 months were -0.44 ng/mL for those receiving placebo, -0.10 ng/mL for those receiving 1000 IU/d, 0 ng/mL for those receiving 2000 IU/d, 1.24 ng/mL for those receiving 4000 IU/d (C-peptide increased 0.42 ng/mL for each additional 1000 IU/d of vitamin D3, p < 0.001). Vitamin D supplementation increased C-peptide in overweight African-Americans and may be compatible with other recommendations for diabetes prevention and management including weight loss and increased physical activity.

Impact of vitamin D supplementation on inflammatory markers in African Americans: results of a four-arm, randomized, placebo-controlled trial.

African Americans have a disproportionate burden of inflammation-associated chronic diseases such as cancer and lower circulating levels of 25-hydroxyvitamin D [25(OH)D]. The effect of vitamin D3 (cholecalciferol) supplementation on inflammatory markers is uncertain. We conducted a randomized, double-blind, placebo-controlled trial of supplemental oral vitamin D (placebo, 1,000, 2,000, or 4,000 IU/day of vitamin D3 orally for 3 months) in 328 African Americans (median age, 51 years) of public housing communities in Boston, MA, who were enrolled over three consecutive winter periods (2007-2010). Change from 0 to 3 months of plasma levels of 25(OH)D, high-sensitivity C-reactive protein (CRP), interleukin (IL)-6, IL-10, and soluble TNF-α receptor type 2 (sTNF-R2) in 292 (89%) participants were measured. Overall, no statistically significant changes in CRP, IL-6, IL-10, and sTNF-R2 were observed after the vitamin D supplementation period. Baseline CRP was significantly inversely associated with the baseline 25(OH)D level (P < 0.001) in unadjusted and adjusted models. An interaction between baseline 25(OH)D and vitamin D supplementation was observed for outcome change in log CRP (month 3-month 0; P for interaction = 0.04). Within an unselected population of African Americans, short-term exposure to vitamin D supplementation produced no change in circulating inflammatory markers. This study confirms the strong independent association of CRP with 25(OH)D status even after adjusting for body mass index. Future studies of longer supplemental vitamin D3 duration are necessary to examine the complex influence of vitamin D3 on CRP and other chronic inflammatory cytokines for possible reduction of cancer health disparities in African Americans.

Declining blood lead and zinc protoporphyrin levels in Ecuadorian Andean children.

OBJECTIVES: To investigate current lead (Pb) exposure in children living in Andean Ecuadorian communities. Blood Pb (PbB) and zinc protoporphyrin (ZPP) levels were used respectively as biomarkers of acute and chronic Pb poisoning. The current PbB-ZPP levels were compared with previous pediatric PbB-ZPP levels recorded over years in the study area. DESIGN AND METHODS: Samples of whole blood were collected from 22 Andean children of Quechua and Mestizo backgrounds and measured for PbB concentrations by graphite furnace atomic absorption spectroscopy. ZPP/heme ratio and ZPP whole blood (ZPP WB) levels were measured with a hematofluorometer. RESULTS: The mean PbB level for children in the current study group was 14.5 µg/dL, which was significantly lower than the mean PbB level of 41.1 µg/dL found in the same study area in the 1996-2000 test period, and lower than the 22.2 µg/dL mean level found in the 2003-2007 period. The current mean ZPP/heme ratio was 102.1 µmol/mol, and the mean ZPP WB level was 46.3 µg/dL, both lower than values previously found in children in the study area. CONCLUSION: While the current pediatric PbB-ZPP levels in the study area remain elevated in some children, the overall levels indicate a decline relative to levels observed in the same Pb-contaminated area in the period between 1996 and 2007. The elevated ZPP levels suggest a history of chronic Pb exposure, and potential iron deficiency in some children. The overall reduction in PbB-ZPP levels suggests a positive outcome of a Pb-exposure education and prevention program, and the therapeutic intervention of succimer chelation therapy.

Plasma folate, vitamin B6, vitamin B12, and homocysteine and pancreatic cancer risk in four large cohorts.

Folate deficiency induces DNA breaks and may alter cellular capacity for mutation and epigenetic methylation. Few studies have examined the influence of one-carbon nutrients on pancreatic cancer risk, although recent studies suggest a potential protective effect for one-carbon nutrients from food sources, but not from supplements. We conducted a prospective nested case-control study to examine plasma concentrations of folate, vitamin B6 [whose main circulating form is pyridoxal-5'-phosphate (PLP)], vitamin B12, and homocysteine in relationship to pancreatic cancer, using four large prospective cohorts. Multivariable adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using conditional logistic regression. All statistical tests were two sided. Among 208 cases and 623 controls, we observed no association between folate, PLP, vitamin B12, or homocysteine and pancreatic cancer risk. Comparing the highest to lowest quartiles of plasma concentration, the ORs were 1.20 (95% CI, 0.76-1.91) for folate, 0.80 (95% CI, 0.51-1.25) for B6, 0.91 (95% CI, 0.57-1.46) for B12, and 1.43 (95% CI, 0.90-2.28) for homocysteine. In analyses restricted to nonusers of multivitamins, we observe a modest inverse trend between folate, PLP, and B12 and pancreatic cancer risk. In contrast, no such inverse associations were observed among study subjects who reported multivitamin supplement use. Among all participants, plasma levels of folate, B6, B12, and homocysteine were not associated with a significant reduction in the risk of pancreatic cancer. Among participants who obtain these factors exclusively through dietary sources, there may be an inverse relation between circulating folate, B6, and B12 and risk.

Long-term prognostic value of neopterin: a novel marker of monocyte activation in patients with acute coronary syndrome.

BACKGROUND: Monocyte activation is believed to play an important role in the pathogenesis of acute coronary syndromes (ACS). Neopterin is a soluble marker of monocyte activation, and elevated levels are of prognostic value in patients with stable coronary artery disease. METHODS AND RESULTS: Neopterin levels were measured on average at 7 days (in 3946 patients) and at 4 months (in 3369 patients) after ACS in the PRavastatin Or atorVastatin Evaluation Infection Therapy-Thrombolysis In Myocardial Infarction (PROVE IT-TIMI 22) trial. We assessed the relationship between plasma neopterin levels and the risk of death and death or acute coronary events (nonfatal myocardial infarction or unstable angina) over 2 years. Seven days after an ACS event, neopterin levels > or = 12.11 nmol/L (upper quartile, derived from a post hoc analysis) were associated with an increased risk of death and an increased risk of death or acute coronary events after adjustment for age, gender, history of diabetes mellitus, history of hypertension, history of smoking, type of ACS presentation, use of percutaneous coronary intervention for the index event, statin regimen, low-density lipoprotein cholesterol, and high-sensitivity C-reactive protein (hazard ratio, 1.86 [95% CI, 1.24 to 2.77], P=0.003; and hazard ratio, 1.33 [95% CI, 1.09 to 1.63] P=0.006, respectively). Neopterin levels > or = 12.11 nmol/L at 4 months remained a predictor of death alone and of death or acute coronary events after multivariable adjustment that included adjustment for month 4 low-density lipoprotein cholesterol, high-sensitivity C-reactive protein, and statin regimen (hazard ratio, 2.39 [95% CI, 1.43 to 3.99], P=0.001; and hazard ratio, 1.60 [95% CI, 1.21 to 2.11], P=0.001). High-dose atorvastatin significantly attenuated the risk among subjects with neopterin levels > or = 12.11 nmol/L at baseline (interaction P for death or acute coronary event, 0.018). CONCLUSIONS: Increased monocyte activation detected by an elevated plasma neopterin level identifies patients at long-term risk of death or recurrent acute coronary events after ACS. Intensive statin therapy significantly attenuates the risk of recurrent events among patients with an elevated neopterin level.

Homocysteine, 5,10-methylenetetrahydrofolate reductase 677C>T polymorphism, nutrient intake, and incident cardiovascular disease in 24,968 initially healthy women.

BACKGROUND: Hyperhomocysteinemia has been associated with a higher risk of cardiovascular disease (CVD) in epidemiological studies, but recent trials have failed to show a benefit of lowering homocysteine. To address this apparent paradox, we explored whether interaction between genetic and dietary factors related to homocysteine metabolism contributes to CVD risk. METHODS: We evaluated the associations of homocysteine, methylenetetrahydrofolate reductase (MTHFR) 677C>T genotype, and dietary intake of folate/B-vitamins with subsequent CVD events in 24 968 apparently healthy white American women followed for 10 years. Plasma homocysteine was measured using an enzymatic assay. MTHFR genotype was determined with a multiplex PCR using biotinylated primers. RESULTS: In unadjusted analyses, homocysteine showed moderately strong linear associations with CVD, with hazard ratios (95% CI) comparing top with bottom quintiles for total CVD of 1.92 (1.55-2.37), myocardial infarction 2.32 (1.52-3.54), and ischemic stroke 2.25 (1.45-3.50), all P(trend) <0.001. These ratios were markedly attenuated after adjusting for traditional risk factors and socioeconomic status to 1.08 (0.86-1.36), P(trend) = 0.12; 1.20 (0.76-1.87), P(trend) = 0.14; and 1.21 (0.75-1.94), P(trend) = 0.50, respectively. Homocysteine was associated with MTHFR genotype (1.4 micromol/L higher homocysteine for TT vs CC, P <0.001) and inversely with intake of folate, vitamin B(2), B(6), and B(12), all P(trend) <0.001. However, there was no association of MTHFR genotype or dietary folate/B-vitamins with CVD. In addition, there were no gene-diet or gene-homocysteine interactions in relation to CVD. CONCLUSIONS: In this large-scale prospective study, the association of homocysteine with CVD was markedly attenuated after adjusting for risk factors and was not modified by MTHFR 677C>T or intake of folate or B-vitamins.

Consumption of (n-3) fatty acids is related to plasma biomarkers of inflammation and endothelial activation in women.

We evaluated the hypothesis that intake of (n-3) fatty acids is inversely associated with biomarkers of inflammation and endothelial activation. We conducted a cross-sectional study of 727 women from the Nurses' Health Study I cohort, aged 43-69 y, apparently healthy at time of a blood draw in 1990. Dietary intake was assessed by a validated FFQ in 1986 and 1990. C-reactive protein (CRP) levels were 29% lower among those in the highest quintile of total (n-3) fatty acids, compared with the lowest quintile; interleukin-6 (IL-6) levels were 23% lower, E-selectin levels 10% lower, soluble intracellular adhesion molecule (sICAM-1) levels 7% lower, and soluble vascular adhesion molecule (sVCAM-1) levels 8% lower. The intake of alpha-linolenic acid was inversely related to plasma concentrations of CRP (beta = -0.55, P = 0.02), Il-6 (beta = -0.36, P = 0.01), and E-selectin (beta = -0.24, P = 0.008) after controlling for age, BMI, physical activity, smoking status, alcohol consumption, and intake of linoleic acid (n-6) and saturated fat. Long-chain (n-3) fatty acids (eicosapentaenoic and docosahexaenoic) were inversely related to sICAM-1 (beta = -0.11, P = 0.03) and sVCAM-1 (beta = -0.17, P = 0.003). Total (n-3) fatty acids had an inverse relation with CRP (beta = -0.44, P = 0.007), IL-6 (beta = -0.26, P = 0.009), E-selectin (beta = -0.17, P = 0.004), sICAM-1 (beta = -0.07, P = 0.02), and sVCAM-1 (beta = -0.10, P = 0.004). These associations were not modified by intake of vitamin E, dietary fiber, trans fatty acids, or by the use of postmenopausal hormone therapy. In conclusion, this study suggests that dietary (n-3) fatty acids are associated with levels of these biomarkers reflecting lower levels of inflammation and endothelial activation, which might explain in part the effect of these fatty acids in preventing cardiovascular disease.

Association between C-reactive protein and age-related macular degeneration.

CONTEXT: C-reactive protein (CRP) is a systemic inflammatory marker associated with risk for cardiovascular disease (CVD). Some risk factors for CVD are associated with age-related macular degeneration (AMD), but the association between CRP and AMD is unknown. OBJECTIVE: To test the hypothesis that elevated CRP levels are associated with an increased risk for AMD. DESIGN, SETTING, AND PARTICIPANTS: A total of 930 (91%) of 1026 participants at 2 centers in the Age-Related Eye Disease Study (AREDS), a multicenter randomized trial of antioxidant vitamins and minerals, were enrolled in this case-control study. There were 183 individuals without any maculopathy, 200 with mild maculopathy, 325 with intermediate disease, and 222 with advanced AMD (geographic atrophy or neovascular AMD). The AMD status was assessed by standardized grading of fundus photographs, and stored fasting blood specimens drawn between January 1996 and April 1997 were analyzed for high-sensitivity CRP levels. MAIN OUTCOME MEASURE: Association between CRP and AMD. RESULTS: The CRP levels were significantly higher among participants with advanced AMD (case patients) than among those with no AMD (controls; median values, 3.4 vs 2.7 mg/L; P =.02). After adjustment for age, sex, and other variables, including smoking and body mass index, CRP levels were significantly associated with the presence of intermediate and advanced stages of AMD. The odds ratio (OR) for the highest vs the lowest quartile of CRP was 1.65 (95% confidence interval [CI], 1.07-2.55; P for trend =.02). The OR for CRP values at or above the 90th percentile (10.6 mg/L) was 1.92 (95% CI, 1.20-3.06), and the OR for CRP values at or above the mean plus 2 SDs (16.8 mg/L) was 2.03 (95% CI, 1.03-4.00). A trend for an increased risk for intermediate and advanced AMD with higher levels of CRP was seen for smokers (OR, 2.16; 95% CI, 1.33-3.49) and those who never smoked (OR, 2.03; 95% CI, 1.19-3.46) with the highest level of CRP. CONCLUSION: Our results suggest that elevated CRP level is an independent risk factor for AMD and may implicate the role of inflammation in the pathogenesis of AMD.

Body iron stores and their determinants in healthy postmenopausal US women.

BACKGROUND: Data on the determinants of body iron stores in middle-aged women are sparse. OBJECTIVE: We prospectively evaluated nondietary and dietary determinants of iron stores. DESIGN: Using blood samples collected in 1989-1990, we measured plasma ferritin concentrations in 620 healthy postmenopausal women aged 44-69 y who participated in the Nurses' Health Study. Food-frequency questionnaires completed in 1980, 1984, and 1986 were used to calculate average dietary intakes. Generalized linear regression and multiple logistic regression models were used to assess the association between plasma ferritin and its determinants. RESULTS: Among these postmenopausal women, the median plasma ferritin concentration was 73.8 ng/mL (interquartile range: 41.6-125.8 ng/mL), 2.7% were iron depleted (ferritin concentration < 12 ng/mL), and 9.8% had an elevated ferritin concentration (> 200 ng/mL). Age, time since menopause, time since the last postmenopausal hormone (PMH) use, body mass index, iron supplement use, and alcohol and heme-iron intakes were positively associated with ferritin concentrations, whereas PMH use, physical activity, aspirin use, and gastrointestinal ulcer were inversely related. The association between heme-iron intake and ferritin was most apparent among the women who consumed > 30 g alcohol/d. CONCLUSIONS: Our prospective data confirm that in postmenopausal women, intakes of heme iron, supplemental iron, and alcohol are dietary determinants of plasma ferritin, and age, PMH use, body mass index, physical activity, aspirin use, and gastrointestinal ulcer are nondietary determinants.

High-dose atorvastatin enhances the decline in inflammatory markers in patients with acute coronary syndromes in the MIRACL study.

BACKGROUND: Inflammation promotes acute coronary syndromes and ensuing clinical complications. Although statins reduce inflammatory markers in asymptomatic adults or in patients with stable angina, the effect of statins on the markedly heightened inflammation in patients with acute coronary syndromes is unknown. METHODS AND RESULTS: We measured C-reactive protein (CRP), serum amyloid A (SAA), and interleukin 6 (IL-6) in 2402 subjects enrolled the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study. Subjects with unstable angina or non-Q-wave myocardial infarction were randomized to atorvastatin 80 mg/d or placebo within 24 to 96 hours of hospital admission and treated for 16 weeks. The effect of treatment on inflammatory markers was assessed by ANCOVA after adjustment for presenting syndrome, country, and initial level of marker. All 3 markers were markedly elevated at randomization and declined over the 16 weeks in both treatment groups. Compared with placebo, atorvastatin significantly reduced CRP, -83% (95% CI, -84%, -81%) versus -74% (95% CI, -75%, -71%) (P<0.0001) and SAA, -80% (95% CI, -82%, -78%) versus -77% (-79%, -75%) (P=0.0006) but not IL-6, -55% (95% CI, -57%, -53%) versus -53% (95% CI, -55%, -51%) (P=0.3). Reductions in CRP and SAA were observed in patients with unstable angina and non-Q-wave myocardial infarction, with initial LDL cholesterol <3.2 or > or =3.2 mmol/L (125 mg/dL), age > or =65 or <65 years, and in men and women. By 16 weeks, CRP was 34% lower with atorvastatin than with placebo. CONCLUSIONS: High-dose atorvastatin potentiated the decline in inflammation in patients with acute coronary syndromes. This supports the value of early statin therapy in these patients.

Habitual dietary intake of n-3 and n-6 fatty acids in relation to inflammatory markers among US men and women.

BACKGROUND: Polyunsaturated fatty acid intake favorably affects chronic inflammatory-related diseases such as cardiovascular disease; however, high intake of n-6 fatty acids may attenuate the known beneficial effects of n-3 fatty acids. METHODS AND RESULTS: We investigated habitual dietary n-3 fatty acid intake and its interaction with n-6 fatty acids in relation to the plasma inflammatory markers C-reactive protein, interleukin 6, and soluble tumor necrosis factor receptors 1 and 2 (sTNF-R1 and R2) among 405 healthy men and 454 healthy women. After adjustment for other predictors of inflammation, intake of the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) was inversely associated with plasma levels of sTNF-R1 and sTNF-R2 (P=0.03 and P<0.001, respectively) and somewhat less so for C-reactive protein (P=0.08). n-3 alpha-linolenic acid and n-6 cis-linoleic acid were not significantly related to the inflammatory markers. We found little if any association between n-3 fatty acid (EPA+DHA) intake and tumor necrosis factor receptors among participants with low intake of n-6 but a strong inverse association among those with high n-6 intake (P=0.04 and 0.002 for interaction of n-3 with n-6 on sTNF-R1 and sTNF-R2, respectively). CONCLUSIONS: These results suggest that n-6 fatty acids do not inhibit the antiinflammatory effects of n-3 fatty acids and that the combination of both types of fatty acids is associated with the lowest levels of inflammation. The inhibition of inflammatory cytokines may be one possible mechanism for the observed beneficial effects of these fatty acids on chronic inflammatory-related diseases.