Testosterone and Sex Hormone–Binding Globulin Predict the Metabolic Syndrome and Diabetes in Middle-Aged MenOBJECTIVE: In men, hypoandrogenism is associated with features of the metabolic syndrome, but the role of sex hormones in the pathogenesis of the metabolic syndrome and diabetes is not well understood. We assessed the association of low levels of testosterone and sex hormone-binding globulin (SHBG) with the development of the metabolic syndrome and diabetes in men. RESEARCH DESIGN AND METHODS: Concentrations of SHBG and total and calculated free testosterone and factors related to insulin resistance were determined at baseline in 702 middle-aged Finnish men participating in a population-based cohort study. These men had neither diabetes nor the metabolic syndrome. RESULTS: After 11 years of follow-up, 147 men had developed the metabolic syndrome (National Cholesterol Education Program criteria) and 57 men diabetes. Men with total testosterone, calculated free testosterone, and SHBG levels in the lower fourth had a severalfold increased risk of developing the metabolic syndrome (odds ratio [OR] 2.3, 95% CI 1.5-3.4; 1.7, 1.2-2.5; and 2.8, 1.9-4.1, respectively) and diabetes (2.3, 1.3-4.1; 1.7, 0.9-3.0; and 4.3, 2.4-7.7, respectively) after adjustment for age. Adjustment for potential confounders such as cardiovascular disease, smoking, alcohol intake, and socioeconomic status did not alter the associations. Factors related to insulin resistance attenuated the associations, but they remained significant, except for free testosterone. CONCLUSIONS: Low total testosterone and SHBG levels independently predict development of the metabolic syndrome and diabetes in middle-aged men. Thus, hypoandrogenism is an early marker for disturbances in insulin and glucose metabolism that may progress to the metabolic syndrome or frank diabetes and may contribute to their pathogenesis.
The Effect of Polyphenols in Olive Oil on Heart Disease Risk FactorsBACKGROUND: Virgin olive oils are richer in phenolic content than refined olive oil. Small, randomized, crossover, controlled trials on the antioxidant effect of phenolic compounds from real-life daily doses of olive oil in humans have yielded conflicting results. Little information is available on the effect of the phenolic compounds of olive oil on plasma lipid levels. No international study with a large sample size has been done. OBJECTIVE: To evaluate whether the phenolic content of olive oil further benefits plasma lipid levels and lipid oxidative damage compared with monounsaturated acid content. DESIGN: Randomized, crossover, controlled trial. SETTING: 6 research centers from 5 European countries. PARTICIPANTS: 200 healthy male volunteers. MEASUREMENTS: Glucose levels, plasma lipid levels, oxidative damage to lipid levels, and endogenous and exogenous antioxidants at baseline and before and after each intervention. INTERVENTION: In a crossover study, participants were randomly assigned to 3 sequences of daily administration of 25 mL of 3 olive oils. Olive oils had low (2.7 mg/kg of olive oil), medium (164 mg/kg), or high (366 mg/kg) phenolic content but were otherwise similar. Intervention periods were 3 weeks preceded by 2-week washout periods. RESULTS: A linear increase in high-density lipoprotein (HDL) cholesterol levels was observed for low-, medium-, and high-polyphenol olive oil: mean change, 0.025 mmol/L (95% CI, 0.003 to 0.05 mmol/L), 0.032 mmol/L (CI, 0.005 to 0.05 mmol/L), and 0.045 mmol/L (CI, 0.02 to 0.06 mmol/L), respectively. Total cholesterol-HDL cholesterol ratio decreased linearly with the phenolic content of the olive oil. Triglyceride levels decreased by an average of 0.05 mmol/L for all olive oils. Oxidative stress markers decreased linearly with increasing phenolic content. Mean changes for oxidized low-density lipoprotein levels were 1.21 U/L (CI, -0.8 to 3.6 U/L), -1.48 U/L (-3.6 to 0.6 U/L), and -3.21 U/L (-5.1 to -0.8 U/L) for the low-, medium-, and high-polyphenol olive oil, respectively. LIMITATIONS: The olive oil may have interacted with other dietary components, participants' dietary intake was self-reported, and the intervention periods were short. CONCLUSIONS: Olive oil is more than a monounsaturated fat. Its phenolic content can also provide benefits for plasma lipid levels and oxidative damage. International Standard Randomised Controlled Trial number: ISRCTN09220811.
Uric Acid Level as a Risk Factor for Cardiovascular and All-Cause Mortality in Middle-aged MenBACKGROUND: Despite abundant epidemiologic evidence, the role of elevated serum uric acid level as a cardiovascular risk factor is controversial. We assessed the predictive value of serum uric acid levels for cardiovascular and overall mortality. METHODS: A population-based prospective cohort study was performed of 1423 middle-aged Finnish men initially without cardiovascular disease, cancer, or diabetes. The main outcome measure was death from cardiovascular disease and any cause. RESULTS: The mean follow-up was 11.9 years. There were 157 deaths during follow-up, of which 55 were cardiovascular. In age-adjusted analyses, serum uric acid levels in the upper third were associated with a greater than 2.5-fold higher risk of death from cardiovascular disease than levels in the lower third. Taking into account cardiovascular risk factors and variables commonly associated with gout increased the relative risk to 3.73. Further adjustment for factors related to the metabolic syndrome strengthened the risk to 4.77. Excluding the 53 men using diuretics did not alter the results. In age-adjusted analyses, men with serum uric acid levels in the upper third were 1.7-fold more likely to die of any cause than men with levels in the lower third. Adjustment for further risk factors strengthened the association somewhat. CONCLUSIONS: Serum uric acid levels are a strong predictor of cardiovascular disease mortality in healthy middle-aged men, independent of variables commonly associated with gout or the metabolic syndrome. Serum uric acid measurement is an easily available and inexpensive risk marker, but whether its relationship to cardiovascular events is circumstantial or causal remains to be answered.
Intake of Mercury From Fish, Lipid Peroxidation, and the Risk of Myocardial Infarction and Coronary, Cardiovascular, and Any Death in Eastern Finnish MenBACKGROUND: Even though previous studies have suggested an association between high fish intake and reduced coronary heart disease (CHD) mortality, men in Eastern Finland, who have a high fish intake, have an exceptionally high CHD mortality. We hypothesized that this paradox could be in part explained by high mercury content in fish. METHODS AND RESULTS: We studied the relation of the dietary intake of fish and mercury, as well as hair content and urinary excretion of mercury, to the risk of acute myocardial infarction (AMI) and death from CHD, cardiovascular disease (CVD), and any cause in 1833 men aged 42 to 60 years who were free of clinical CHD, stroke, claudication, and cancer. Of these, 73 experienced an AMI in 2 to 7 years. Of the 78 decreased men, 18 died of CHD and 24 died of CVD. Men who had consumed local nonfatty fish species had elevated hair mercury contents. In Cox models with the major cardiovascular risk factors as covariates, dietary intakes of fish and mercury were associated with significantly increased risk of AMI and death from CHD, CVD, and any death. Men in the highest tertile (> or = 2.0 micrograms/g) of hair mercury content had a 2.0-fold (95% confidence interval, 1.2 to 3.1; P = .005) age- and CHD-adjusted risk of AMI and a 2.9-fold (95% CI, 1.2 to 6.6; P = .014) adjusted risk of cardiovascular death compared with those with a lower hair mercury content. In a nested case-control subsample, the 24-hour urinary mercury excretion had a significant (P = .042) independent association with the risk of AMI. Both the hair and urinary mercury associated significantly with titers of immune complexes containing oxidized LDL. CONCLUSIONS: These data suggest that a high intake of mercury from nonfatty freshwater fish and the consequent accumulation of mercury in the body are associated with an excess risk of AMI as well as death from CHD, CVD, and any cause in Eastern Finnish men and this increased risk may be due to the promotion of lipid peroxidation by mercury.
Kuopio Atherosclerosis Prevention Study (KAPS)BACKGROUND: The atherosclerotic progression-reducing effect of LDL cholesterol (LDL-C) lowering has been established in subjects with severe atherosclerotic disease but not in persons with elevated LDL cholesterols without severe atherosclerosis. KAPS (Kuopio Atherosclerosis Prevention Study) is the first population-based trial in the primary prevention of carotid and femoral atherosclerosis. METHODS AND RESULTS: The eligibility requirements were serum LDL-C > or = 4.0 mmol/L and total cholesterol < 7.5 mmol/L. Out of a geographically defined population, 447 men aged 44 to 65 years (mean, 57) were randomized to pravastatin (40 mg/d) or placebo for 3 years. Less than 10% of the subjects had prior myocardial infarction. Thirty-nine men discontinued study medication; however, efficacy data were available for 424 men. The primary outcome was the rate of carotid atherosclerotic progression, measured as the linear slope over annual ultrasound examinations in the average of the maximum carotid intima-media thickness (IMT) of the far wall of up to four arterial segments (the right and left distal common carotid artery and the right and left carotid bulb). For the carotid arteries, at the overall mean baseline IMT of 1.66 mm, the rate of progression of carotid atherosclerosis was 45% (95% CI, 16 to 69%) less in the pravastatin (0.017 mm/y) than the placebo (0.031 mm/y) group (P = .005). In the common carotid artery there was a treatment effect of 66% (95% CI, 30 to 95%; pravastatin 0.010 mm/y; placebo 0.029 mm/y; P < .002) at the overall mean baseline IMT of 1.35 mm. A treatment effect of 30% (95% CI, -1% to 54%) was found for the carotid bulb (pravastatin, 0.028; placebo, 0.040; P = .056) at the overall mean baseline IMT of 2.0 mm. The treatment effect was larger in subjects with higher baseline IMT values, in smokers and in those with low plasma vitamin E levels. There was no significant treatment effect on atherosclerotic progression in the femoral arteries. CONCLUSIONS: These data establish the antiatherogenic effect of LDL-C lowering by pravastatin in hypercholesterolemic men in a primary prevention setting and suggest a greater effect in smokers than in nonsmokers.