Changes in body weight in relation to mortality in 6441 European middle-aged men: the Seven Countries Study.

OBJECTIVES: To study the relation between changes in body weight and subsequent mortality. DESIGN: Prospective follow-up study. SETTING: Population study. SUBJECTS: 6441 men aged 40-59 y at baseline participating in the European cohorts of the Seven Countries Study. The men were divided into groups depending on their weight pattern ascertained from three weight measurements with intervals of 5 years. They were also divided in quartiles according to the degree of weight variability. MAIN OUTCOME MEASURES: All-cause and cause-specific mortality during 15 years following the last weight measurement. Deaths occurring during the first 5 years of follow-up were excluded. RESULTS: Significantly elevated hazard ratios (RR) for death from all causes (RR = 1.3; 95% confidence interval (CI): 1.2-1.5), all cardiovascular diseases (RR = 1.2; 95% CI: 1.0-1.5) and other causes (RR = 1.6; 95% CI: 1.2-2.2) were found for men with a decreasing weight compared with men with a constant weight. A fluctuating weight was associated with an increased risk of all cause mortality (RR = 1.2; 95% CI: 1.0-1.4), coronary heart disease (RR = 1.5; 95% CI: 1.0-1.9) and myocardial infarction (RR = 1.5; 95% CI: 1.0-2.2). The group of men with an increasing body weight also had elevated hazard ratios for dying from coronary heart disease and myocardial infarction, but these were only significant when the total 15-year follow-up was analyzed. The risks of dying from all-causes, cardiovascular disease, cancer and other causes were increased in the upper quartile versus the lower quartile of weight variability. CONCLUSIONS: The results of the present study show that a decreasing and a fluctuating body weight are associated with increased mortality. An average increase of 7 kg body weight was associated with an elevated risk of dying from coronary heart disease and myocardial infarction. Lowest mortality in these middle-aged men was found in those who maintained a constant body weight.

Multifrequency bioelectrical impedance as a measure of differences in body water distribution.

In 38 females, aged 21.3 +/- 1.8 years (mean +/- SD) and 22 males, aged 21.6 +/- 2.0 years, total body water (TBW) was assessed by bioelectrical impedance at a frequency of 100 kHz (Z100), and extracellular water (ECW) was assessed at a frequency of 1 (Z1) or 5 kHz (Z5). Impedance ratios of low frequencies (Z1 or Z5) to high frequency (Z100) were calculated as indicators of body water distribution. Furthermore, changes in body water distribution during the menstrual cycle were assessed in 16 females, aged 22.1 +/- 1.7 years, divided into subjects using or not using oral contraceptives. In general, the ratio ECW to TBW was lower in males compared to females, which was reflected in the ratios Z1/Z100 and Z5/Z100. However, the ratio Z5/Z100 reflected this difference less clear, probably because at 5 kHz the current partly passes the cell membranes. Weight changes during the menstrual cycle are generally accepted to be due to a retention of ECW. The ratio Z5/Z100 and the ratios Z1/Z100 and Z5/Z100 for those subjects not using oral contraceptives differed significantly between day with minimal and day with maximal weight. A negative correlation was found between weight change, still considering day with minimal and day with maximal weight, and change in impedance at 5 and 50 kHz for subjects not using oral contraceptives. It is concluded that differences in body water distribution are reflected by low-to-high impedance ratios.

Health of experimental animals drinking water with and without amosite asbestos and other mineral particles.

In view of diseases associated with inhalation of asbestos fibers, interest attaches to the question of whether risks are presented by ingestion of asbestos or mineralogically related fibrous-shaped particles reported in drinking water supplies. Experimental animals (hamsters) were maintained on filtered drinking water with and without addition of mineral particles. A peritoneal mesothelioma, pulmonary carcinoma and two early squamous cell carcinomas of the forestomach were found in hamsters so exposed to a preparation of amosite asbestos. These tumors could not be specifically attributed to amosite, but they show that hamsters of the strain used were capable of developing tumors of particular interest in this experiment. No deleterious health effects and no tumors related to treatment were found in hamsters exposed to milled taconite ore containing fibrous-shaped particles of cummingtonite/grunerite, mineralogically related to amosite but in shorter lengths more comparable in size to fibers associated with drinking water supplies.