Elevated Cystatin C Concentration and Progression to Pre-Diabetes

Abstract

OBJECTIVE— We conducted a nested case-control investigation to examine whether elevated baseline concentrations of cystatin C predicted progression from normoglycemia to pre-diabetes over 6 years of follow-up from the Western New York Health Study. RESEARCH DESIGN AND METHODS— In 2002–2004, 1,455 participants from the Western New York Health Study, who were free of type 2 diabetes and known cardiovascular disease at baseline (1996–2001), were reexamined. An incident case of pre-diabetes was defined as an individual with fasting glucose <100 mg/dl at the baseline examination and ≥100 and ≤125 mg/dl at the follow-up examination, thereby eliminating individuals with prevalent pre-diabetics. All case patients (n = 91) were matched 1:3 to control participants based on sex, race/ethnicity, and year of study enrollment. All control subjects had fasting glucose levels <100 mg/dl at both baseline and follow-up examinations. Cystatin C concentrations and the urinary albumin-to-creatinine ratio were measured from frozen (−196°C) baseline blood and urine samples. Serum creatinine concentrations were available from the baseline examination only. RESULTS— Multivariate conditional logistic regression analyses adjusted for age, baseline glucose level, homeostasis model assessment of insulin resistance, BMI, hypertension, estimated glomerular filtration rate, cigarette smoking, and alcohol use revealed a significantly increased risk of progression to pre-diabetes among those with elevated baseline concentrations of cystatin C (odds ratio 3.28 [95% CI 1.43–7.54]) (upper quintile versus the remainder). Results of secondary analyses that considered high-sensitivity C-reactive protein, interleukin-6, E-selectin, or soluble intercellular adhesion molecule-1 did not alter these results. CONCLUSIONS— These results suggest that cystatin C was associated with a threefold excess risk of progression to pre-diabetes in this population.