(AVP)(p) was markedly elevated after the ultramarathon despite unchanged plasma [Na(+)](.) Therefore, an inability to maximally suppress (AVP)(P) during exercise as a result of nonosmotic stimulation of AVP secretion may contribute to the pathogenesis of exercise-associated hyponatremia if voluntary fluid intake were to exceed fluid output.

Objectives-To test the association between inorganic lead (Pb) exposure, blood pressure, and renal function in South African battery factory workers, with both conventional and newer measures of renal function and integrity. Methods-Renal function measures included serum creatinine, urea, and urate (n = 382). Urinary markers (n = 199) included urinary N-acetyl--Dglucosaminidase (NAG), retinol binding protein, intestinal alkaline phosphatase, tissue non-specific alkaline phosphatase, Tamm-Horsfall glycoprotein, epidermal growth factor, and microalbuminuria. Results-Mean current blood Pb was 53.5 µg/dl (range 23 to 110), median zinc protoporphyrin 10.9 µg/g haemoglobin (range 1.9 to 104), and mean exposure duration 11.6 years (range 0.5 to 44.5). Mean historical blood Pb, available on 246 workers, was 57.3 µg/dl (range 14 to 96.3). After adjustment for age, weight and height, positive exposure response relations were found between current blood Pb, historical blood Pb, zinc protoporphyrin (ZPP), and serum creatinine and urate. Blood pressure was not associated with Pb exposure. Among the urinary markers, only NAG showed a positive association with current and historical blood Pb. Conclusion-An exposure-response relation between Pb and renal dysfunction across the range from <40 to >70 µg/dl blood Pb was found in this workforce, with conventional measures of short and long term Pb exposure and of renal function. This could not be explained by an eVect on blood pressure, which was not associated with Pb exposure. The findings probably reflect a higher cumulative renal burden of Pb absorption in this workforce in comparison with those in recent negative studies. The results also confirm the need for strategies to reduce Pb exposure among industrial workers in South Africa. (Occup Environ Med 1998;55:453-460)

The Coronary Risk Factor Study (CORIS) examined the feasibility and effectiveness of a multifactorial community intervention programme to reduce coronary heart disease (CHD) risk factor levels. Three Afrikaner communities were surveyed before and after a 4-year intervention in two of the communities, the third serving as a control (C). Intervention was primarily by small mass media (low-intensity intervention, LII) or by small mass media plus interpersonal intervention to high-risk individuals (high-intensity intervention, HII). After allowing for change in C, significant net reductions in blood pressure, smoking, and risk score were obtained in LII and HII alike. Though the total cholesterol (TC) fell by 10-12%, there was no net reduction in favour of the intervention communities. However, LII and HII resulted in significant increases in high-density lipoprotein cholesterol (HDL-C) levels and HDL-C/TC ratios in comparison to C. Overall, the LII community fared almost as well as the HII community, and high-risk individuals did not show a greater change in risk factors than others. We conclude that community-based intervention works, and that in these particular communities a media-based health education programme was more cost-effective than one which adds a greater degree of interpersonal intervention.

We sought to (a) replicate and (b) extend (via the addition of alcohol use) Cha et al.'s cross-sectional multi-component model of ART adherence on the relationship between social support, depression, self-efficacy beliefs, and antiretroviral therapy (ART) adherence, among HIV patients in Tshwane, South Africa. Using purposive sampling, 304 male and female ART recipients were recruited. ART adherence was assessed using three manifest indicators: total adherence ratio, the CASE adherence index and 1-month adherence measure. Data were analysed using structural equation modeling. In our replicated model, social support had both direct and indirect relationships with ART adherence, and inclusion of alcohol use improved prediction of ART adherence. Direct and indirect effects of alcohol use on ART adherence emerged: adherence self-efficacy beliefs partially mediated the latter path. Findings highlight the importance of integrating into ART promotion interventions, the reduction of alcohol use, provision of social support, and enhancement of adherence self-efficacy beliefs.

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