Serum leptin levels in older patients with hip fracture--impact on peri-operative myocardial injury.

To evaluate whether there is a relationship between admission serum leptin concentrations and peri-operative myocardial injury, 238 consecutive older patients (mean age 81.9+/-7.9 years; 172 women) with low-trauma hip fracture were assessed. Myocardial injury as defined by elevated serum cardiac troponin I was associated with lower leptin levels analyzed as continuous or categorical variables. Patients with serum leptin concentrations <12ng/ml (medium value) had a two-fold greater increased risk for such complications compared with those with higher leptin levels (odd ratio 2.13, 95% confidence interval 1.06-4.28; p=0.033). This association remained significant after adjustments for age, gender, clinical (history of coronary artery disease [CAD], stroke, hypertension, diabetes, dementia), hematological (red, white, and lymphocyte count, hemoglobin, hematocrit), metabolic (parathyroid hormone [PTH], albumin), renal(creatinine, urea, glomerular filtration rate [GFR]), and inflammatory (C-reactive protein [CRP], ferritin) factors. The predictive value of lower leptin levels increased significantly when used in combination with traditional risk factors for myocardial injury.