Serum homocysteine, folate and risk of stroke: Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study.

BACKGROUND: Homocysteine and folate have been suggested to have opposite effects on the risk of stroke, although the results are controversial. DESIGN AND METHODS: The purpose of this study was to assess the effects of serum total homocysteine (tHcy) and serum folate levels on the risk of stroke in a prospective cohort study. The subjects were 1015 men aged 46-64 years and free of prior stroke, examined in 1991-1993 in the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study. RESULTS: At baseline the mean serum tHcy concentration was 10.9 micromol/l (SD 3.4). During an average follow-up time of 9.6 years, 49 men experienced a stroke, of which 34 were ischaemic. In Cox proportional hazards models, men in the highest tHcy third had a risk factor-adjusted hazard rate ratio (RR) of 2.77 [95% confidence interval (CI): 1.23-6.24] for any stroke and 2.61 (95% CI: 1.02-6.71) for ischaemic stroke, compared with men in the lowest third. The mean baseline serum folate concentration was 10.4 nmol/l (SD 4.1). Men in the highest third of serum folate (>11.2 nmol/l) had an adjusted RR for any stroke of 0.35 (95% CI: 0.14-0.87) and for ischaemic stroke of 0.40 (95% CI: 0.15-1.09), compared with men in the lowest third. CONCLUSION: Elevated serum tHcy is associated with increased risk of all strokes and ischaemic strokes in middle-aged eastern Finnish men free of prior stroke. On the other hand, high serum folate concentration may protect against stroke.     

Associations between serum homocysteine, holotranscobalamin, folate and cognition in the elderly: a longitudinal study

Abstract. Hooshmand B, Solomon A, Kåreholt I, Rusanen M, Hänninen T, Leiviskä J, Winblad B, Laatikainen T, Soininen H & Kivipelto M (Aging Research Center, Karolinska Institutet, Stockholm, Sweden; KI Alzheimer’s Disease Research Center (KI‐ADRC), Karolinska Institutet, Stockholm, Sweden; National Institute for Health and Welfare (THL), Helsinki, Finland; University of Eastern Finland, Institute of Clinical Medicine, and University Hospital, Kuopio, Finland). Associations between serum homocysteine, holotranscobalamin, folate and cognition in the elderly: a longitudinal study. J Intern Med 2012; 271 : 204–212. Objectives. To examine the associations between serum homocysteine (tHcy), holotranscobalamin (holoTC, the biologically active fraction of vitamin B12) and folate and cognitive functioning in a longitudinal population‐based study of Finnish elderly subjects. Subjects and design. tHcy, holoTC and folate were measured at baseline in 274 dementia‐free subjects aged 65–79 years from the Cardiovascular Risk Factors, Aging and Dementia study. Subjects were re‐examined 7 years later, and global cognition, episodic memory, executive functioning, verbal expression and psychomotor speed were assessed. Results. Higher baseline tHcy levels were associated with poorer performance in global cognition, relative difference: 0.90 [95% confidence interval (CI) 0.81–0.99]; episodic memory: 0.87 (95% CI 0.77–0.99); executive functions: 0.86 (95% CI 0.75–0.98); and verbal expression: 0.89 (95% CI 0.81–0.97) at follow‐up. Increased holoTC levels were related to better performance on global cognition: 1.09 (95% CI 1.00–1.19); executive functions: 1.11 (95% CI 1.01–1.21); and psychomotor speed: 1.13 (95% CI 1.01–1.26). After excluding 20 cases of incident dementia, increased tHcy remained associated with poorer performance in episodic memory, execution functions and verbal expression. Higher holoTC levels tended to be related to better performance in executive functions and psychomotor speed, while elevated serum folate concentrations were significantly related to higher scores in global cognition and verbal expression tests. Conclusions. tHcy, holoTC and folate levels are related to cognitive performance 7 years later even in nondemented elderly subjects. Randomized trials are needed to determine the impact of vitamin B12 and folate supplementation on preventing cognitive decline in the elderly.     

The effect of the C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase gene on homocysteine levels in elderly men and women from the British regional heart study

Total blood levels of homocysteine (tHcy) have been shown to depend on both environmental and genetic factors, and to be associated with the risk of developing atherosclerosis with its complications of coronary heart disease (CHD) and stroke. In this study, 408 men and 346 women from two towns, Dewsbury and Maidstone were examined for tHcy levels and genotyped for the C677T and the A1298C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene. Blood tHcy was significantly higher in men from the CHD high risk town of Dewsbury (12.7 micromol/l) than in the low CHD risk town of Maidstone (11.5 micromol/l) P<0.001, but not in women (10.7 vs. 10.5 micromol/l), with women in both towns, thus, showing significantly lower tHcy than men. There was no difference between towns in folate or vitamin B12 levels but the conventional inverse relationship with tHcy was seen. Smoking men and women from both towns had significantly higher tHcy and lower folate levels than non-smoking individuals (P<0.001). The frequency of the 677T allele in Dewsbury was 0.35 (95% CI; 0.32-0.39) compared with 0.29 (95% CI; 0.26-0.32) in Maidstone (P<0.01). Similar frequency difference of borderline statistical significance was seen both for men (P=0.054) and women (P=0.048) in both the towns, suggesting a true regional frequency difference. The effect of the 677T on tHcy was highly significant in the group as a whole with the most profound effect seen in men (12.0 micromol/l for CC vs. 14.1 micromol/l for TT, P<0.001). By contrast, there was no significant effect of the A1298C polymorphism on tHcy, folate or vitamin B12 levels, with no evidence for an interaction with the C677T genotype. The regional differences in tHcy levels were still present after the adjustment for folate and vitamin B12 levels, smoking and the effect of the C677T polymorphism. This suggests that there may be other unidentified factors, either environmental or genetic, affecting tHcy levels, and thus potentially having an impact on the risk of developing hyperhomocysteinaemia and CHD. These observations may have a bearing on regional differences in tHcy levels and the variation in CHD risk between regions in the UK.     

Serum folate and cardiovascular disease mortality among US men and women

BACKGROUND: Folate has been linked to cardiovascular disease (CVD) through its role in homocysteine metabolism. OBJECTIVE: To assess the relationship between serum folate and CVD mortality. DESIGN: In this prospective study, serum folate concentrations were measured on a subset of adults during the Second National Health and Nutrition Examination Survey (1976-1980) and vital status ascertained after 12 to 16 years. SETTING AND PATIENTS: A national probability sample consisting of 689 adults who were 30 to 75 years of age and did not have a history of CVD at baseline. MAIN OUTCOME MEASURE: Vital status was determined by searching national databases that contained information about US decedents. RESULTS: The associations between serum folate and CVD and all-cause mortality differed by diabetes status (P =.04 and P =.03, respectively). Participants without diabetes in the lowest compared with the highest serum folate tertile had more than twice the risk of CVD mortality after adjustment for age and sex (relative risk [RR], 2.64; 95% confidence interval [CI], 1.15-6.09). This increased risk for participants in the lowest tertile was attenuated after adjustment for CVD risk factors (RR, 2.28; 95% CI, 0.96-5.40). Serum folate tertiles were not significantly associated with total mortality, although the age- and sex-adjusted risk was increased for participants in the lowest compared with highest tertile (RR, 1.74; 95% CI, 0.96-3.15). Risk estimates for participants with diabetes were unstable because of the small sample size (n = 52). CONCLUSION: These data suggest that low serum folate concentrations are associated with an increased risk of CVD mortality among adults who do not have diabetes. Arch Intern Med. 2000;160:3258-3262.     

Both vitamin B6 and total homocysteine plasma levels predict long-term atherothrombotic events in healthy subjects.

AIMS: The contribution of homocysteine and group B vitamins in determining cardiovascular risk is debated. We assessed the predictive value of total homocysteine (tHcy), vitamin B12, folate, and vitamin B6 on the long-term occurrence of coronary and cerebral atherothrombotic events in a nested case-control study. METHODS AND RESULTS: Within a cohort of 1021 healthy subjects (490 men and 531 women) recruited in 1987, 66 first-ever coronary and 43 first-ever cerebrovascular events were recorded at a 12-year follow-up (cases, n=109). A total of 109 control subjects (remaining free from events) were matched with cases according to age, sex, smoking, hypertension, dyslipidaemia, and body mass index. Serum samples obtained in 1987 at baseline were used to measure tHcy, folate, and vitamins B12 and B6, as well as C-reactive protein plasma concentrations. We found a significant graded association between tHcy levels and the risk of coronary and cerebrovascular events [odds ratio (OR) for uppermost vs. lowermost quartile=1.34, 95% CI 1.01-1.76)]. Folate and vitamin B12 did not significantly differ between cases and controls, but were negatively (P<0.01) correlated with tHcy. Vitamin B6 did not correlate with tHcy levels, but differed significantly between cases and controls: for subjects in the uppermost quartile vs. the lowermost quartile of vitamin B6, OR=0.69 (95% CI 0.49-0.98). For subjects in the lowermost quartile of vitamin B6 and the uppermost quartile of tHcy, OR=17.50 (95% CI 1.97, 155.59). Cases and controls were not different as to C-reactive protein. CONCLUSION: tHcy and plasma vitamin B6 are long-term independent risk factors for coronary and cerebrovascular events.     

Modulation of the homocysteine-betaine relationship by methylenetetrahydrofolate reductase 677 C->t genotypes and B-vitamin status in a large-scale epidemiological study

CONTEXT: Betaine is formed from the essential nutrient choline or is supplied from the diet. It serves as a substrate in the betaine-homocysteine methyltransferase reaction and thereby provides methyl groups for the homocysteine-methionine cycle, which is regulated by enzymes dependent on folate, vitamin B12, riboflavin (vitamin B2), or vitamin B6. OBJECTIVE: We investigated how betaine affected total homocysteine (tHcy) concentration within the frame of variable B-vitamin status and according to the methylenetetrahydrofolate reductase (MTHFR) 677C->T genotype. DESIGN/SETTING/PATIENTS: This is a population-based study with a cross-sectional design. It includes 10,601 healthy men and women aged 50-64 yr. OUTCOME MEASURES: Plasma samples were analyzed for tHcy, betaine, choline, dimethylglycine, riboflavin, and vitamin B6, whereas folate and vitamin B12 were analyzed in serum. RESULTS: Betaine was a strong determinant of plasma tHcy in subjects with low serum folate and the MTHFR TT genotype. The association was further strengthened at low levels in the circulation of the other B-vitamins (B2, B6, and B12). Thus, in subjects with the combination of serum folate in the lowest quartile, low vitamin B2, B6, and B12 status, and the MTHFR TT genotype, the difference in tHcy (mean, 95% confidence interval) across extreme plasma betaine quartiles was 8.8 (1.3-16.2) micromol/liter. CONCLUSION: Betaine may thus be an important one-carbon source, particularly in MTHFR 677 TT subjects with inadequate B-vitamin status.     

Homocysteine levels and lacunar brain infarcts in elderly women: the prospective population study of women in Gothenburg

OBJECTIVES: To examine whether total serum homocysteine (tHcy) in a population-based sample of middle-aged women is an independent risk factor for presence of lacunar infarcts (LIs) 24 years later.
DESIGN: Prospective population study, follow-up time 24 years.
SETTING: Gothenburg, an urban area in western Sweden.
PARTICIPANTS: Five hundred twenty-six women, 89.6% of the original study sample of the Population Study of Women in Gothenburg, aged 46 to 60 at baseline in 1968/69 and re-examined at age 70 to 84.
MEASUREMENTS: After 24 years of follow-up, all subjects underwent a psychiatric examination, and 277 computerized tomography (CT) scans of the brain were performed. Two radiologists assessed LIs and white matter lesions (WMLs). Baseline serum tHcy was analyzed from frozen stored serum samples. Logistic regression analyses were performed controlling for potential confounders such as age and selected cardiovascular risk factors.
RESULTS: Thirty-four subjects had LIs in 1992 (12.3%). In the full multivariate-adjusted stepwise model, LIs were associated with elevated tHcy (odds ratio (OR)=1.09, 95% confidence interval (CI)=1.01–1.17 per μmol/L of tHcy increment). Women with tHcy values in the highest tertile were almost three times as likely to have LIs (OR=2.82, 95% CI=1.34–5.93) as were those in the lowest tertile. tHcy was not related to WMLs. Subjects who did not undergo a CT scan did not differ from those who did regarding tHcy or any of the covariates studied.
CONCLUSION: tHcy in middle-aged women is an independent risk factor for LIs, but not WMLs, as observed using CT later in life.     

Folate and risk of coronary heart disease: a meta-analysis of prospective studies

Background and aimsEpidemiologic studies are inconsistent regarding the association between folate and coronary heart disease (CHD) risk. The aim was to perform a meta-analysis to determine whether an association exists between folate and total CHD endpoints in prospective studies.Methods and resultsWe searched the PUBMED and EMBASE databases for studies conducted from 1966 through August 2010. Data were independently abstracted by 2 investigators using a standardized protocol. Study-specific risk estimates were combined by using a random effects model.A total of 14 studies were included in the meta-analysis: 7 studies on dietary folate intake and 8 studies on blood folate levels. For dietary intake, the summary relative risk (RR) indicated a significant association between the highest folate intake and reduced risk of CHD (summary RR: 0.69; 95% CI: 0.60, 0.80). Furthermore, an increase in folate intake of 200 ug/day was associated with a 12% decrease in the risk of developing CHD (summary RR: 0.88; 95% CI: 0.82, 0.94). For blood folate levels, we also found a borderline inverse association of highest blood folate levels on CHD risk (summary RR: 0.74; 95% CI: 0.53, 1.02); our dose-response analysis indicated that an increment in blood folate levels of 5 mmol/l was associated with an 8% decrease in the risk of developing CHD (summary RR: 0.92; 95% CI: 0.84, 1.00).ConclusionThis meta-analysis suggests that dietary folate intake and blood folate level are inversely associated with CHD risk.     

Homocysteine as a risk factor for coronary heart diseases and its association with inflammatory biomarkers, lipids and dietary factors

The causal relation of total Homocysteine (tHcy) to coronary heart diseases (CHD) is unclear. In vitro studies suggest a proinflammatory effect. Among 32,826 women from the Nurses' Health Study who provided blood samples in 1989-1990, 237 CHD events were documented during 8 years of follow-up. The cases (1:2) were matched to controls on age, smoking, and month of blood draw. Plasma tHcy was inversely associated with blood levels of folate (partial r = -0.3, P < 0.0001) and B1(2) (r = -0.2, P < 0.0001) and with dietary intake of folate (r = -0.1, P < 0.01) and B(2) vitamin (r = -0.1, P = 0.01). tHcy was positively associated with soluble tumor necrosis receptor (sTNF-R) 1 and 2 (partial r = 0.2, P < 0.0001). In a multivariate model adjusted for age, smoking, BMI, parental history, hypertension, diabetes, postmenopausal hormone use, physical activity and alcohol intake, the relative risk of CHD between the extreme quartiles of tHcy was 1.66 (95% CI; 1.05-2.64, P trend = 0.02). The association was not appreciably attenuated after further adjustments for sTNF-R1, sTNF-R2, CRP, or Total Cholesterol:/HDL-c ratio. tHcy is an independent risk predictor of CHD and modestly associated with TNF-receptors. However, the inflammatory biomarkers measured could not explain its role in CHD.     

Complement factor H (Y402H) polymorphism and risk of coronary heart disease in US men and women.

AIMS: Complement factor H (CFH) Y402H polymorphism is located in a region that binds C-reactive protein and may affect inflammatory processes and risk of coronary heart disease (CHD). We assessed the association between Y402H and risk of CHD in nested case-control studies among two large prospective cohorts of US male health professionals and female nurses. METHODS AND RESULTS: Among participants who were disease-free at baseline, we confirmed 266 (men) and 249 (women) incident CHD deaths and non-fatal myocardial infarctions (MIs) over 6 and 8 years of follow-up, respectively. Using risk-set sampling, controls were matched 2:1 on the basis of age, smoking, and date of blood draw. Comparing homozygous HH with YY, the relative risk (RR) of CHD was 0.94 [95% confidence interval (CI) 0.59-1.49] among men and 0.51 (95% CI 0.29-0.89) among women (pooled RR 0.73, 95% CI 0.51-1.04). The HH genotype was inversely associated with CHD among those <65 years at onset (men: RR 0.39, 95% CI 0.16-0.95; women: 0.21, 95% CI 0.07-0.65; pooled: 0.30, 95% CI 0.15-0.61), but not among those > or =65 years (pooled RR 1.09, 95% CI 0.71-1.68). CONCLUSION: CFH Y402H was inversely associated with CHD among women, but not men. This inverse association was observed in both populations with earlier age of CHD.     

Long-Term Changes in Gut Microbial Metabolite Trimethylamine N-Oxide and Coronary Heart Disease Risk

BackgroundA gut-microbial metabolite, trimethylamine N-oxide (TMAO), has been associated with coronary atherosclerotic burden. No previous prospective study has addressed associations of long-term changes in TMAO with coronary heart disease (CHD) incidence.ObjectivesThe purpose of this study was to investigate whether 10-year changes in plasma TMAO levels were significantly associated with CHD incidence.MethodsThis prospective nested case-control study included 760 healthy women at baseline. Plasma TMAO levels were measured both at the first (1989 to 1990) and the second (2000 to 2002) blood collections; 10-year changes (Δ) in TMAO were calculated. Incident cases of CHD (n = 380) were identified after the second blood collection through 2016 and were matched to controls (n = 380).ResultsRegardless of the initial TMAO levels, 10-year increases in TMAO from the first to second blood collection were significantly associated with an increased risk of CHD (relative risk [RR] in the top tertile: 1.58 [95% confidence interval (CI): 1.05 to 2.38]; RR per 1-SD increment: 1.33 [95% CI: 1.06 to 1.67]). Participants with elevated TMAO levels (the top tertile) at both time points showed the highest RR of 1.79 (95% CI: 1.08 to 2.96) for CHD as compared with those with consistently low TMAO levels. Further, we found that the ΔTMAO-CHD relationship was strengthened by unhealthy dietary patterns (assessed by the Alternate Healthy Eating Index) and was attenuated by healthy dietary patterns (p interaction = 0.008).ConclusionsLong-term increases in TMAO were associated with higher CHD risk, and repeated assessment of TMAO over 10 years improved the identification of people with a higher risk of CHD. Diet may modify the associations of ΔTMAO with CHD risk.     

Serum uric acid shows a J-shaped trend with coronary mortality in non-insulin-dependent diabetic elderly people. The CArdiovascular STudy in the ELderly (CASTEL)

The relationship between serum uric acid (SUA) and risk of coronary heart disease (CHD) mortality remains controversial, particularly in diabetic subjects. The aim of the present study is to evaluate whether SUA independently predicts CHD mortality in non-insulin-dependent elderly people from the general population and to investigate the interactions between SUA and other risk factors. Five hundred and eighty-one subjects aged ≥65 years with non-insulin-dependent diabetes mellitus were prospectively studied in the frame of the CArdiovascular STudy in the ELderly (CASTEL). Historical and clinical data, blood tests and 12-year fatal events were recorded. SUA as a continuous item was divided into tertiles and, for each tertile, adjusted relative risk (RR) with 95% confidence intervals (CI) was derived from multivariate Cox analysis. CHD mortality was predicted by SUA in a J-shaped manner. Mortality rate was 7.9% (RR 1.28, CI 1.05–1.72), 6.0% (reference tertile) and 12.1% (RR 1.76, CI 1.18–2.27) in the increasing tertiles of SUA, respectively, without any difference between genders. In diabetic elderly subjects, SUA independently predicts the risk of CHD mortality in a J-shaped manner.     

Age, sex and vitamin status affect plasma level of homocysteine, but hyperhomocysteinaemia is possibly not an important risk factor for venous thrombophilia in Taiwanese Chinese

The biological effects of age, sex and vitamin status on plasma total homocysteine (tHcy), and association of hyperhomocysteinaemia with venous thromboembolism in Taiwanese Chinese individuals, were investigated. Eighty patients (16-85 years) with venous thrombophilia and 123 healthy subjects (15-85 years) without history of vascular thrombosis were studied for plasma levels of tHcy, folate and vitamin B12. A multivariate analysis in healthy subjects revealed that plasma tHcy levels tended to increase with age (P < 0.001) and with decreasing plasma levels of folate (P=0.001) or vitamin B12 (P < 0.029); men tended to have higher plasma tHcy levels than women (P=0.006). Thrombotic risk assessment in a case-control study demonstrated that neither plasma level of tHcy [odds ratio (OR), 1.07; 95% confidence interval (CI), 0.96-1.18; P=0.210] nor hyperhomocysteinaemia (OR, 1.65; 95% CI, 0.50-5.49; P=0.415) was significantly associated with venous thrombophilia. The relationship between hyperhomocysteinaemia and recurrence of episode remained insignificant (P=0.560). We conclude that age, sex and vitamin status affect plasma tHcy but hyperhomocysteinaemia is possibly not an important risk factor for venous thrombophilia in Taiwanese Chinese.     

Body mass index, body cell mass, and 4-year all-cause mortality risk in older nursing home residents

OBJECTIVES: To investigate the relationship between body composition (assessed using body mass index (BMI) and body cell mass (BCM)) and all-cause mortality in a sample of older nursing home residents. DESIGN: Prospective study with a median follow-up period of 3.5 years. SETTING: Istituto di Riposo per Anziani, Padua, Italy. PARTICIPANTS: A total of 344 participants (79.1% women) aged 65 and older at baseline. MEASUREMENTS: Anthropometric, nutritional, and metabolic parameters were measured at baseline. BCM was measured using tetrapolar bioelectric impedance analysis. Up to 4 years of follow-up data for vital status were available. Survival analysis was conducted using Kaplan-Meier curves and multivariate Cox proportional hazards models. RESULTS: During the follow-up period, there were 179 deaths. After adjustment for age and sex, subjects with low BMI and low BCM (lowest sex-specific tertiles) had significantly higher mortality than those with higher BMI or BCM levels. In a fully adjusted regression model, there was no association between BMI levels and risk of mortality, with subjects in the top tertile having the same likelihood of mortality as subjects in the lowest tertile (relative risk (RR)=0.94, 95% confidence interval (CI)=0.61-1.43). Conversely, there was a strong and significant inverse association between BCM levels and mortality (RR for tertile III=0.55, 95% CI=0.35-0.87; P<.01). Furthermore, participants who had high BCM had comparable survival rates in all BMI tertiles. CONCLUSION: In this sample of older nursing home residents, BCM was a strong and independent risk factor for mortality. BCM assessment might provide more useful prognostic information for clinicians than BMI.     

Methylenetetrahydrofolate reductase mutation (677C-->T) negatively influences plasma homocysteine response to marginal folate intake in elderly women

Individuals who are homozygous for the methylenetetrahydrofolate reductase (MTHFR) 677C --> T mutation have depressed serum folate (SF) and elevated plasma total homocysteine (tHcy) concentrations, which may affect folate requirements and increase the risk for coronary artery disease. A controlled metabolic study (14 weeks) using a depletion/repletion protocol was performed in women (aged 60 to 85 years, N = 33) to provide age-specific data on the effects of the MTHFR mutation on SF and tHcy status. Subjects consumed a moderately folate-deplete diet (118 microg/d) for 7 weeks, followed by 7 weeks of folate repletion with 200 or 415 microg/d provided as two different treatments. Following folate depletion, the mean SF concentration was lower for homozygous (P = .017) versus heterozygous subjects. Homozygotes for the 677C --> T mutation showed a higher (P = .015) percent increase in plasma tHcy (44%) than heterozygous (20%) or normal (15%) subjects. At week 7, the mean plasma tHcy concentration was higher in homozygous subjects (12.5 +/- 5.3 micromol/L, mean +/- SD) versus the heterozygous (10.8 +/- 3.8 micromol/L, P = .008) or normal (11.3 +/- 2.7 micromol/L, P = .001) genotype groups. Following folate repletion, plasma tHcy concentrations were not different between genotype groups, despite a higher (P < .016) SF concentration in subjects with the homozygous genotype. These data suggest that older women who are homozygous for the MTHFR 677C --> T mutation may be at risk for greater elevations in plasma tHcy in response to moderately low folate intake as compared with individuals with the normal or heterozygous genotypes.     

Estradiol and its metabolites and their association with knee osteoarthritis

OBJECTIVE: To determine if levels of endogenous estrogen or estrogen metabolites are associated with an increased risk of developing knee osteoarthritis (OA) in women. METHODS: Serum estradiol (E2) and 2 urinary estrogen metabolites (2-hydroxyestrone and 16alpha-hydroxyestrone) with radiographically defined prevalent and incident knee OA in 842 white and African American women from the Southeast Michigan Arthritis Cohort. RESULTS: The mean age and body mass index (BMI) of women in the cohort were 42.3 years and 28.5 kg/m2, respectively. Women who developed radiographically defined knee OA had significantly greater odds of having baseline endogenous early follicular phase estradiol concentrations in the lowest tertile (<47 pg/ml; odds ratio [OR] 1.88, 95% confidence interval [95% CI] 1.07-3.51) compared with those with estradiol concentrations in the middle tertile [47-77 pg/ml]), after adjustment for age, BMI, and other covariates. Women who developed knee OA also had greater odds of having baseline urinary concentrations of 2-hydroxyestrone in the lowest tertile (OR 2.9, 95% CI 1.49-5.68) compared with women with 2-hydroxyestrone concentrations in the middle tertile), after adjustment for covariates. Women who developed knee OA were more likely to have a ratio of 16alpha-hydroxyestrone to 2-hydroxyestrone in the highest tertile (>0.86; OR 1.86, 95% CI 1.01-3.44 compared with women with ratios in the 0.54-0.86 range), after adjustment for other covariates. CONCLUSION: There were significant associations of lower baseline serum estradiol and urinary 2-hydroxyestrone with developing knee OA in middle-aged women.     

Incidence and predictors of hypertension over 8 years among Chinese men and women

OBJECTIVE: To determine the 8-year incidence of hypertension and its risk factors among Chinese adults. METHODS: A population-based sample of 10,525 Chinese adults aged > or = 40 years and free from hypertension at baseline was followed up from 1991 to 1999-2000. Incident hypertension was defined as systolic pressure > or = 140 mmHg, diastolic pressure > or = 90 mmHg, or current use of antihypertensive medication. RESULTS: Over a mean of 8.2 years of follow-up, 28.9% of men and 26.9% of women developed hypertension. Among men, independent predictors of incident hypertension were baseline age [relative risk (RR) per 5 years: 1.10; 95% confidence interval (CI): 1.07, 1.13], living in urban regions versus rural regions (RR: 0.74; 95% CI: 0.64, 0.85), alcohol drinking versus non-drinking (RR: 1.13; 95% CI: 1.02, 1.24), prehypertension versus normotension (RR: 1.70; 95% CI: 1.53, 1.88), heart rate (RR of third versus first tertile: 1.27; 95% CI: 1.13, 1.44), body mass index (RR of third versus first tertile: 1.28; 95% CI: 1.12, 1.46) and low versus high physical activity (RR: 1.27; 95% CI: 1.10, 1.47). Results were similar for women, with current smoking in place of alcohol drinking and opposite results for region. The population-attributable risk of modifiable risk factors was between 25 and 50%. CONCLUSIONS: These data indicate that the incidence of hypertension is high among these Chinese adults, and suggest that 25-50% of new hypertension cases could be prevented with risk factor modification. Given the excess cardiovascular mortality associated with hypertension, these data call for urgent improvements in hypertension prevention and control programs in China.     

Fatty liver and uric acid levels predict incident coronary heart disease but not stroke among atomic bomb survivors in Nagasaki.

Relationships between fatty liver and coronary heart disease (CHD) and stroke risk remain ill defined. We investigated whether fatty liver is a predictor of CHD and stroke risk. Until December 2000 we followed 2,024 atomic bomb survivors (775 men: 62.0 +/- 9.9 years old; 1,249 women: 63.2 +/- 8.4 years old) who had basic examinations between November 1990 and October 1992 for clinical and laboratory CHD risk factors and fatty liver and who were initially free of CHD and stroke. Forty-nine cases of CHD and 84 cases of stroke were observed. At the time of the baseline examinations, significant clinical associations were found between fatty liver and obesity (p<0.001), hypertension (p<0.001), dyslipidemia (p<0.001), and glucose intolerance (p<0.001). A slight but nonsignificant association was found between fatty liver and hyperuricemia (p=0.07) as well. By using multiple Cox regression analyses, age (relative risk [RR] 1.05, 95% confidence interval [CI] 1.01-1.08), smoking (RR 2.20, 95% CI 1.02-4.74), hyperuricemia (RR 2.30, 95% CI 1.08-4.89), and fatty liver (RR 2.53, 95% CI 1.06-6.06) were shown to be significant predictors of CHD, whereas age (RR 1.08, 95% CI 1.06-1.10), smoking (RR 2.06, 95% CI 1.14-3.72), and hypertension (RR 2.14, 95% CI 1.38-3.30) predicted stroke risk. Fatty liver, which clusters clinical and laboratory CHD risk factors, is an independent predictor of CHD, but not of stroke. Fatty liver should be followed as a feature of metabolic syndrome, with the aim of preventing CHD.     

Plasma total homocysteine level and bone mineral density: the Hordaland Homocysteine Study

BACKGROUND: Plasma total homocysteine (tHcy) has been associated with hip fracture but not directly with bone mineral density (BMD). We examined the association of hip BMD with levels of plasma tHcy, folate, and vitamin B12 and the methylenetetrahydrofolate reductase (MTHFR) 677C-->T and 1298A-->C polymorphisms. METHODS: Bone mineral density was measured between 1997 and 2000 in 2268 men and 3070 women, aged 47 to 50 and 71 to 75 years, from the Hordaland Homocysteine Study cohort. Low BMD was defined as BMD in the lowest quintile for each sex and age group. Linear, logistic, and generalized additive regression models were used. RESULTS: Plasma levels of tHcy were inversely related to BMD among middle-aged and elderly women (P<.001) but not among men. The multiple adjusted odds ratio for low BMD among subjects with high (>or=15 micromol/L [>or=2.02 mg/L]) compared with low (<9 micromol/L [<1.22 mg/L]) tHcy level was 1.96 (95% confidence interval, 1.40-2.75) for women and was not significant for men. Additional adjustments for plasma folate level or intake of calcium and vitamin D did not substantially alter the results. Plasma folate level was associated with BMD in women only. We observed no association between BMD and vitamin B12 level or the MTHFR polymorphisms. CONCLUSIONS: Elevated tHcy and low folate levels were associated with reduced BMD in women but not in men. These findings suggest that tHcy may be a potential modifiable risk factor for osteoporosis in women.