Abstract 2904: Deficiency in Circulating Testosterone Predicts Reduction in Exercise Capacity in Men in the Course of Chronic Heart Failure
Background. Multiple anabolic deficiency (expressed as reduced serum levels of testosterone, dehydroepiandrosterone sulphate [DHEAS], insulin-like growth factor 1 [IGF1]) is related to high mortality in men with chronic heart failure (CHF). Exercise intolerance constitutes a fundamental feature of CHF syndrome. So far, the effects of anabolic deficiency on exercise capacity have not been studied in men with CHF.
Methods. We examined 205 men with stable systolic CHF (mean age: 60±11 years, NYHA class [I-II/III-IV]: 132/73; median LVEF: 30%, 71% of ischaemic aetiology). Exercise capacity was expressed as peak oxygen consumption (peak VO2, mL/min/kg and % of age-predicted values). Serum levels of total testosterone (TT), DHEAS, IGF1 were measured using immunoassays. Serum levels of free testosterone were estimated (eFT) from TT and sex hormone binding globulin levels.
Results. In multivariable stepwise regression models, in men with CHF, reduced peak VO2 was determined independently by:
diminished serum TT (r=0.18, p=0.002) and eFT (r=0.23, p<0.0001);
CHF severity -advanced NYHA class (r=-0.37, p<0.0001) and high plasma NT-proBNP (r=-0.20, p=0.0007); and 3) age (r=-0.13, p=0.03) (but not by CHF aetiology, LVEF, and serum levels of other hormones - all p>0.2).
All these associations remained significant also after adjustment for an amount of leg muscle mass. Analogous results were obtained when both peak VO2 and serum levels of anabolic hormones were expressed as % of age-predicted values. In 44 men with CHF, who were reassessed after 2.3±0.5 years, a reduction in peak VO2 in the course of disease was determined only by a decrease in serum TT (r=0.52, p=0.0003) and eFT (r=0.58, p<0.0001) (but neither by change in NYHA class nor plasma NT-proBNP).
Conclusions. In men with CHF, circulating testosterone constitutes an independent major determinant of their exercise capacity. Moreover, the greater the reduction of serum testosterone in the course of CHF, the more severe the progression of exercise intolerance. Whether a supplementation of deficient androgen would improve exercise capacity in men with CHF, needs to be established in further studies.