Leg length, insulin resistance, and coronary heart disease risk: The Caerphilly Study

Background-Adult height has been inversely associated with coronary heart d isease risk in several studies. The mechanism for this association is not w ell understood, however, and this was investigated by examining components of stature, cardiovascular disease risk factors and subsequent coronary hea rt disease in a prospective study. Methods-All men aged 45-59 years living in the town of Caerphilly, South Wa les were approached, and 2512 (89%) responded and underwent a detailed exam ination, which included measurement of height and sitting height (from whic h an estimate of leg length was derived). Participants were followed up thr ough repeat examinations and the cumulative incidence of coronary heart dis ease-both fatal and non-fatal-over a 15 year follow up period is the end po int in this report. Results-Cross sectional associations between cardiovascular risk factors an d components of stature (total height, leg length and trunk length) demonst rated that factors related to the insulin resistance syndrome-the homeostas is model assessment of insulin resistance, fasting triglyceride levels and total to HDL cholesterol ratio-were less favourable in men with shorter leg s, while showing reverse or no associations with trunk length. Fibrinogen l evels were inversely associated with leg length and showed a weaker associa tion with trunk length. Forced expiratory volume in one second was unrelate d to leg length but strongly positively associated to trunk length. Other r isk factors showed little association with components of stature. The risk of coronary heart disease was inversely related to leg length but showed li ttle association with trunk length. Conclusion-Leg length is the component of stature related to insulin resist ance and coronary heart disease risk. As leg length is unrelated to lung fu nction measures it is unlikely that these can explain the association in th is cohort. Factors that influence leg length in adulthood-including nutriti on, other influences on growth in early life, genetic and epigenetic influe nces-merit further investigation in this regard. The reported associations suggest that pre-adult influences are important in the aetiology of coronar y heart disease and insulin resistance.