Several important effect modifications of these relationships were found by sex (for the associations with UCP1 and UCP3) and RF including smoking (for the associations with SIRT5 and UCP4), hypertension (for the associations with SIRT3, SIRT5, and UCP5), and diabetes (for the associations with SIRT5 and UCP5). The gene discussed is UCP1; the disease is diabetes mellitus.