Association between serum homocysteine and markers of impaired kidney function in adults in the United States

Association between serum homocysteine and markers of impaired kidney function in adults in the United States.BackgroundCirculating homocysteine, a risk factor for cardiovascular disease (CVD), is often elevated in chronic kidney disease and end-stage renal disease (ESRD) patients. Little is known about the risk of elevated homocysteine associated with less advanced renal insufficiency in the community.MethodsSerum homocysteine concentration measures (umol/L) from the National Health and Nutrition Examination Survey (NHANES) 1991–1994 participants who were aged ≥40 years and fasted ≥6 hours (1558 men and 1829 women) were categorized as <9, 9 to 11.9, 12 to 14.9, and ≥15. Renal function levels were determined by Modified Diet in Renal Disease (MDRD) estimated glomerular filtration rate (GFRest) (mL/min/1.73 m2) and the urinary albumin-to-creatinine ratio (ACR) (mg/g). Cumulative odds ratios (OR) of exceeding any given homocysteine cut point were computed by gender, using ordinal logistic regression. Each model included GFRest (<60, 60 to 90, ≥90), ACR (<15, 15 to <30, ≥30), age, race/ethnicity, red blood cell folate, serum vitamin B12, and dietary vitamin B6 intake as independent variables.ResultsThe adjusted ORs for elevated homocysteine risk were 9 to 11 times greater in adults with the lowest GFRest levels (