Age and kidney function are the primary correlates of fasting plasma total homocysteine levels in non-diabetic and diabetic adults. Results from the 1999–2002 National Health and Nutrition Examination Survey

Abstract

Abstract Background Plasma total homocysteine (tHcy) is commonly elevated in persons with diabetes. This may be due to effects of insulin and/or glucose and/or metabolic control on the metabolism or plasma levels of tHcy. This study examined the effects of fasting plasma glucose status on fasting tHcy levels among adults without diabetes, and diabetes per se among adults with a self-report history of diabetes. Methods Analysis of data on adults (≥ 20y) who had fasted at least 8 hours, from the National Health and Nutrition Examination Survey (1999–2000 and 2001–2002). Subjects with no self-report history of diabetes were grouped according to fasting plasma glucose status as normal (n = 2,244), impaired (≥ 100 n = 1,108), or a provisional diagnosis of diabetes (≥ 126 mg/dL = DFG, n = 133). Subjects with a self-report history of diabetes (n = 275) were examined separately. Results Fasting tHcy was higher (Ps r = 0.38 to 0.44 and r = -0.35 to -0.46, respectively) and diabetic subjects (r = 0.41 and r = -0.46, respectively) (Ps 1c) were weaker (but still significant) correlates of tHcy in non-diabetic and diabetic subjects. Fasting glucose status was not a significant independent predictor of fasting tHcy levels in non-diabetic subjects, and HbA1c was not a significant independent predictor of tHcy in diabetic subjects (Ps > 0.05). Conclusion Fasting tHcy levels are elevated among non-diabetic adults with elevated fasting glucose levels, compared to persons with normal fasting glucose levels, and among diabetic adults. However, elevations in fasting tHcy appear to be mediated primarily by age and kidney function, and not by measures of glucose metabolism.