Impaired glucose metabolism - A potential risk factor for idiopathic nodular glomerulosclerosis: A single center study

Nodular glomerulosclerosis is a characteristic histological finding of diabetic nephropathy (DN) with thickened glomerular basement membrane and hyalinized arterioles. Idiopathic nodular glomerulosclerosis (ING), a distinct clinicopathologic entity, is the term used to denote classic DN confirmed by light microscopy, immuno-fluorescence, and electron microscopy but in the absence of diabetes mellitus (DM). ING has been linked to heavy tobacco smoking, chronic hypertension, and obesity. We report the result of a retrospective study identifying seventeen subjects from Thomas Jefferson University (1999-2014) with biopsy-proven nodular glomerulosclerosis but no pre-existing history of DM. The main indications for percutaneous kidney biopsy (PKB) were either reduced renal function or the presence of proteinuria. The subjects' mean (±SD) age was 60.2 (14.4) years, their highest documented random glucose level was 104.4 (23.5) mg/dL, serum creatinine measured 2.35 (1.03) mg/dL, and body mass index calculated 29.4 (6.2) kg/m2. None of the patients fulfilled criteria for diabetes at the time of PKB. However, review of medical records revealed history of intermittently elevated blood glucose or borderline-high HgbA1c levels. The role of impaired glucose metabolism or insulin resistance, as a possible etiology for ING is potentially underestimated and needs additional studies.