Abdominal obesity is associated with potassium depletion and changes in glucose homeostasis during diuretic therapy

The activation of the renin-angiotensin system (RAS) is an important mechanism that contributes to hypertension in obese individuals. Thiazide diuretics also activate the RAS in response to volume contraction and can lead to a decrease in serum potassium values and glucose metabolism abnormalities. To evaluate the impact of abdominal obesity on potassium depletion and glucose homeostasis in hypertensive patients receiving thiazide therapy, the authors studied 329 hypertensive patients without known diabetes or impaired renal function. Patients were stratified into 2 major groups according to whether they used thiazide diuretic therapy, and each group was further divided in 2 subgroups according to the presence of abdominal obesity. The authors demonstrated that obese patients receiving diuretic therapy had lower plasma potassium levels and higher glucose values compared with nonobese patients receiving diuretic therapy. In conclusion, abdominal obesity predisposes to potassium depletion during diuretic therapy in association with effects on glucose homeostasis.     

Diagnosing abnormal glucose tolerance in hypertensive women: are we making the best choice?

Essential hypertension is a condition of peripheral insulin resistance; thus, fasting plasma glucose level (FPG) alone may not identify glucose tolerance abnormalities. To evaluate the value of an FPG of 100 mg/dL in the detection of these abnormalities in hypertensive women and to identify clinical markers of a high risk of glucose intolerance indicative of further investigation, the authors studied 313 hypertensive women, without known diabetes, in whom an oral glucose tolerance test (OGTT) was performed. The authors demonstrated that FPG alone was not sufficient to identify 27.6% of hypertensive women with glucose intolerance. In this subgroup, the association of waist circumference >or=97 cm and FPG >or=100 mg/dL increased the risk of glucose intolerance with an odds ratio of 6.97. The authors suggest that OGTT should be performed in hypertensive women with normal FPG but with FPG >or=90 mg/dL or waist circumference >or=97 cm.     

Applying Mendelian randomization to appraise causality in relationships between nutrition and cancer

Cancer Causes & Control - Dietary factors are assumed to play an important role in cancer risk, apparent in consensus recommendations for cancer prevention that promote nutritional changes....     

A prospective cohort study of the combined effects of physical activity and anthropometric measures on the risk of post-menopausal breast cancer

Although keeping a healthy weight and being physically active are among the few modifiable risk factors for post-menopausal breast cancer, the possible interaction between these two risk factors remains to be established. We analyzed prospectively a cohort of 19,196 women who provided detailed self-report on anthropometric measures, physical activity and possible confounders at enrollment in 1997. We achieved complete follow-up through 2010 and ascertained 609 incident cases of post-menopausal invasive breast cancer. We calculated metabolic energy turnover (MET h/day) per day and fitted Cox proportional hazards models to estimate hazard ratios (HRs) with 95 % confidence intervals (CIs). The incidence of post-menopausal breast cancer among obese women (BMI ≥ 30 kg/m²) was 58 % higher (HR 1.58, CI 1.16–2.16) than in women of normal weight (18.5 ≤ BMI < 25). Women in the lowest tertile of total physical activity (< 31.2 MET h/day) had 40 % higher incidence of post-menopausal breast cancer (HR 1.40, CI 1.11–1.75) than those in the highest tertile (≥ 38.2 MET h/day). The excess incidence linked to these two factors seemed to combine in an approximately additive manner; the incidence among the most obese and sedentary women was doubled (HR 2.07, CI 1.31–3.25) compared with the most physically active women with normal weight. No heterogeneity of the physical activity-linked risk ratios across strata of BMI was detected (p value for interaction = 0.98). This prospective study revealed dose-dependent, homogenous inverse associations between post-menopausal breast cancer incidence and physical activity across all strata of BMI, and between post-menopausal breast cancer incidence and BMI across all strata of physical activity, with no evidence of additive or multiplicative interaction between the two, suggesting independent effects.