Serum resistin and glomerular filtration rate in patients with type 2 diabetes.

BACKGROUND: High serum levels of the pro-inflammatory adipokine resistin have been associated with decreased renal function in the general population. The goal of this study was to investigate whether such association is also present among diabetic subjects, who are at increased risk of renal function loss. METHODS: The cross-sectional association between serum resistin levels and estimated glomerular filtration rate (eGFR) was investigated in 1,560 type 2 diabetic (T2D) patients of European ancestry comprised in two different cohorts: 762 patients from San Giovanni Rotondo (SGR; Italy) and 798 patients from Boston (US). RESULTS: Serum resistin was inversely associated with eGFR in SGR [β (SE) for one SD of resistin increment = -1.01 (0.70) ml/min/1.73 m(2), p = 0.019] and in Boston [β (SE) = -5.31 (0.74) ml/min/1.73 m(2), p < 0.001] samples, as well as in the two studies combined [β (SE) = -3.42 (0.52) ml/min/1.73 m(2), p < 0.001]. The association was unaffected by adjustment for smoking habits, BMI, waist circumference, diabetes duration, HbA1c, insulin treatment, hypertension and lipid-lowering therapy: β (SE) for one SD of resistin increment = -1.07 (0.70), p = 0.02; -5.50 (0.88), p < 0.001; and -2.81 (0.55) ml/min/1.73 m(2), p < .001, in SGR, Boston and the two studies combined, respectively. The association was significantly stronger in men than in women (p for resistin-by-gender interaction = 0.003). For each resistin SD increment, the odds of having eGFR < 0 ml/min/1.7 3m(2) increased by 22% (OR = 1.22; 95% CI 1.02-1.44; p = 0.025) in SGR sample, 69% (OR = 1.69; 95% CI 1.38-2.07; p < 0.001) in Boston sample, and 47% (OR = 1.47; 95% CI 1.29-1.68; p < 0.001) in the two studies considered together. Similar associations were observed in the adjusted model: OR 95% CI for each SD resistin increment being 1.23 (1.03-1.46), p = 0.021; 1.52 (1.20-1.92), p < 0.001; 1.33 (1.16-1.53), p < 0.001, in SGR, Boston and the two studies combined, respectively. CONCLUSIONS: This is the first report of an association between high serum resistin and low eGFR in patients with T2D of European ancestr