Plasma Homocysteine Levels Do Not Increase Significantly Across the Spectrum of Glucose Tolerance: the Framingham Offspring Study – Abstract
James B Meigs
Glucose intolerance and elevated plasma homocysteine (Hcy) levels are both cardiovascular disease (CVD) risk factors. Little is known about the relationships between glucose intolerance and Hcy levels. We measured clinical characteristics, fasting levels of plasma Hcy, vitamins involved in Hcy metabolism (folate, [B.sub.12], and pyridoxal-5′-phosphate), plasma creatinine, and glucose tolerance status (with an OGTT using 1997 ADA criteria) in 2220 subjects free of CVD at the 5th examination (1991-1995) of the community-based Framingham Offspring Study. Subjects were classified with diagnosed (Dx) or undiagnosed (Undx) type 2 diabetes (DM), impaired glucose tolerance (IGT), or normal glucose tolerance (NGT). Those with NGT were further classified into quintiles of fasting glucose (N1-N5). Age, sex-, creatinine-, and vitamin level-adjusted geometric mean Hcy levels or proportions with Hcy [is greater than] 14 [micro]mol/L in each category, and trends across categories, were assessed with linear or logistic regression models. Mean age of participants was 54 yrs (range 28-82); 54% were women. The prevalence of DM was 8% (4.9% Undx) and of IGT, 15%. Adjusted mean Hcy levels or proportions with Hcy levels [is greater than] 14 [micro]mol/L (Table) did not increase significantly across the spectrum of glucose tolerance from N1 to IGT, Undx DM, or Dx DM. Further adjustment for body mass index or fasting insulin levels did not alter these effects. We conclude that abnormalities in fasting plasma Hcy levels are unrelated to glucose tolerance status; these two risk factors probably exert independent effects on development of CVD. Whether further adjustment for subtle, unmeasured declines in renal function might reveal an effect of glucose intolerance on Hcy levels remains to be explored.
N1 N2 N3 N4
Hcy [micro] mol/L) 9.6 9.4 9.3 9.3
Hcy >14 (%) 12 11 9 9
N5 IGT Undx Dx
Hcy [micro] mol/L) 9.5 9.7 9.8 10.2
Hcy >14 (%) 10 12 12 13
ADA Funded Research
JAMES B MEIGS(*), PAUL JACQUES, JACOB SELHUB, PATRICIA MURPHY-SHEEHY, DAVID NATHAN(*), DANIEL SINGER(*), RALPH D’AGOSTINO, PETER WILSON(*), Boston, MA
(*) ADA Professional Section Member. See Duality of Interest Information.
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