The non-genetic determinants of central adiposity.

Central adiposity carries an increased risk of non-insulin dependent diabetes mellitus (NIDDM), cardiac disease, hypertension and death, and is closely related to insulin resistance. Genetic factors explain a large proportion of the population variance in central adiposity, although the genotypic characteristics remain obscure. Hormonal factors such as endogenous sex steroid levels, the menopause, hormone replacement therapy and cortisol may influence body fat partitioning. The link between dietary factors and central adiposity is controversial, with contradictory results in the literature. Smoking is associated with lower total body fat, but investigations of its influence on central adiposity have also yielded contradictory results. Higher levels of physical activity are associated with lesser amounts of central fat, both cross-sectionally and in intervention studies. Some of the contradictory results regarding putative influences on central adiposity may be due to limitations of some of the anthropometric parameters of central adiposity, such as the waist-hip ratio. Further research is required to clarify the relationships between many of these factors and with both compartments of central adiposity: subcutaneous abdominal and intraabdominal adipose tissue.