Dietary magnesium intake, serum high sensitivity C-reactive protein and the risk of incident knee osteoarthritis leading to hospitalization-A cohort study of 4,953 Finns.

OBJECTIVES: To study whether low dietary magnesium (Mg) intake and serum high sensitivity C-reactive protein (hs-CRP) predict the development of clinical knee osteoarthritis (OA). METHODS: The cohort consisted of 4,953 participants of a national health examination survey who were free of knee and hip OA at baseline. Information on the incidence of knee OA leading to hospitalization was drawn from the National Care Register for Health Care. During the follow-up of 10 years, 123 participants developed incident knee OA. Dietary magnesium intake was assessed on the basis of a food frequency questionnaire from the preceding year. We used Cox's proportional hazards model to estimate the strength of the association between the tertiles of dietary Mg intake and incident knee OA, adjusted for baseline age, gender, energy intake, BMI, history of physical workload, leisure time physical activity, injuries, knee complaints, the use of Mg supplements, and serum hs-CRP levels. RESULTS: At baseline, dietary Mg intake was inversely associated with serum hs-CRP even after adjustment for all the potential confounding factors. During the follow-up, the adjusted hazard ratios (with their 95% confidence intervals) for incident knee OA in dietary Mg intake tertiles were 1.00, 1.28 (0.78-2.10), and 1.38 (0.73-2.62); the p value for trend was 0.31. Serum hs-CRP level at baseline did not predict incident knee OA. CONCLUSIONS: The results do not support the hypothesis that low dietary Mg intake contributes to the development of clinical knee OA, although Mg intake is inversely associated with serum hs-CRP level.

Selenium and Prostate Cancer: Analysis of Individual Participant Data From Fifteen Prospective Studies.

BACKGROUND: Some observational studies suggest that a higher selenium status is associated with a lower risk of prostate cancer but have been generally too small to provide precise estimates of associations, particularly by disease stage and grade. METHODS: Collaborating investigators from 15 prospective studies provided individual-participant records (from predominantly men of white European ancestry) on blood or toenail selenium concentrations and prostate cancer risk. Odds ratios of prostate cancer by selenium concentration were estimated using multivariable-adjusted conditional logistic regression. All statistical tests were two-sided. RESULTS: Blood selenium was not associated with the risk of total prostate cancer (multivariable-adjusted odds ratio [OR] per 80 percentile increase = 1.01, 95% confidence interval [CI] = 0.83 to 1.23, based on 4527 case patients and 6021 control subjects). However, there was heterogeneity by disease aggressiveness (ie, advanced stage and/or prostate cancer death, Pheterogeneity = .01), with high blood selenium associated with a lower risk of aggressive disease (OR = 0.43, 95% CI = 0.21 to 0.87) but not with nonaggressive disease. Nail selenium was inversely associated with total prostate cancer (OR = 0.29, 95% CI = 0.22 to 0.40, Ptrend < .001, based on 1970 case patients and 2086 control subjects), including both nonaggressive (OR = 0.33, 95% CI = 0.22 to 0.50) and aggressive disease (OR = 0.18, 95% CI = 0.11 to 0.31, Pheterogeneity = .08). CONCLUSIONS: Nail, but not blood, selenium concentration is inversely associated with risk of total prostate cancer, possibly because nails are a more reliable marker of long-term selenium exposure. Both blood and nail selenium concentrations are associated with a reduced risk of aggressive disease, which warrants further investigation.

QRS-T angle as a predictor of sudden cardiac death in a middle-aged general population.

AIMS: Spatial QRS-T angle measured from a 12-lead electrocardiogram (ECG) has been shown to predict cardiac mortality. However, there is a paucity of studies on the prognostic significance of frontal QRS-T angle, which is more readily available from the standard 12-lead ECG. The purpose of the present study was to investigate the importance of wide frontal QRS-T angle, QRS-axis, and T-wave axis as cardiac risk predictors in general population. METHODS AND RESULTS: We evaluated the 12-lead ECGs of 10 957 Finnish middle-aged subjects from the general population recorded between 1966 and 1972, and followed them for 30 ± 11 years. QRS-T angle 0 to 90°, QRS-axis -30 to 90°, and T-wave axis 0 to 90° were considered normal. The primary endpoint was death from arrhythmia, and the secondary endpoints were all-cause mortality and non-arrhythmic cardiac mortality. QRS-T angle ≥ 100° was present in 2.0% of the subjects, and it was associated with an increased risk of sudden arrhythmic death [relative risk (RR) 2.26; 95% confidence interval (CI) 1.59-3.21; P< 0.001) and all-cause mortality (RR 1.57; CI 1.34-1.84; P< 0.001), but not with non-arrhythmic cardiac mortality (RR 1.34; CI 0.93-1.92; P= 0.13). The prognostic significance of wide QRS-T angle was mainly due to abnormal T-wave axis, which predicted death from arrhythmia (RR 2.13; CI 1.63-2.79; P< 0.001), all-cause mortality (RR 1.39; 1.24-1.55; P< 0.001), and non-arrhythmic cardiac death (RR 1.87; CI 1.50-2.34; P< 0.001). CONCLUSION: Frontal QRS-T angle ≥ 100° increases the risk of arrhythmic death, this being mainly the result of an altered T-wave axis.

Intake of fish and long-chain n-3 fatty acids and the risk of coronary heart mortality in men and women.

This prospective study investigated the relationship between the consumption of fish and intake of long-chain n-3 fatty acids and the risk of coronary heart mortality in 2775 men and 2445 women aged from 30 to 79 years who were free of CHD and had participated in a health examination survey from 1967 to 1972. In total, 335 men and 163 women died of CHD during a follow-up until the end of 1992. A dietary history interview method provided data on habitual consumption of fish and other foods over the preceding year at baseline. The intakes of long-chain n-3 fatty acids were calculated on the basis of food composition values of Finnish foods. Higher consumption of fish was associated with a decreased risk of CHD among women, whereas no significant association was seen among men. The relative risk between the highest and the lowest quintile for fish consumption was 1.00 (95 % CI 0.70, 1.43; P for trend 0.83) for men and 0.59 (95 % CI 0.36, 0.99; P for trend 0.02) for women in analysis adjusting for age, energy intake, geographical area, BMI, serum cholesterol, blood pressure, smoking, occupation and diabetes; however, after adjustment for dietary confounders this association was no longer significant. The intake of n-3 fatty acids was not significantly associated with the risk of CHD in either men or women. In conclusion, our results for women are in line with the suggested protective effect of fish consumption against CHD but a similar association was not, however, found in men.

Serum fatty acids and breast cancer incidence.

Fatty acid composition of the diet may be essential to the development of breast cancer. We studied the ability of several fatty acids of serum total lipids to predict breast cancer incidence in a case-control study nested within a longitudinal population study. The proportions of fatty acids in serum total lipids were determined from stored serum samples collected at baseline for 127 incident breast cancer cases and 242 matched controls. Women with a higher proportion of total polyunsaturated fatty acids (PUFAs) in serum had a reduced risk of breast cancer. The odds ratio (OR) between the highest and lowest tertiles of serum PUFA was 0.31 (95% confidence interval, CI = 0.12-0.77). This association was mainly due to n-6 PUFAs and especially to linoleic acid. The ORs were 0.35 (CI = 0.14-0.84) and 0.29 (CI = 0.12-0.73), respectively. Of the monounsaturated fatty acids (MUFAs), higher trans-11-18:1 levels were related to an increased breast cancer risk (OR = 3.69, CI = 1.35-10.06). The association was stronger in postmenopausal than in premenopausal women. The present study suggests that higher serum proportions of the n-6 PUFA linoleic acid and lower proportions of the MUFA trans-11-18:1 fatty acid predict a reduced incidence of breast cancer.