Vitamin D and 1-hour post-load plasma glucose in hypertensive patients

Cardiovasc Diabetol. 2014 Feb 20:13:48. doi: 10.1186/1475-2840-13-48.

Abstract

Background: A plasma glucose value ≥155 mg/dl for 1-hour post-load plasma glucose during an oral glucose tolerance test (OGTT) is able to identify subjects with normal glucose tolerance (NGT) at high-risk for type-2 diabetes and with subclinical organ damage. We designed this study to address if 25-hydroxyvitamin D [25(OH)D] circulating levels are associated with glucose tolerance status, and in particular with 1-hour post-load plasma glucose levels.

Methods: We enrolled 300 consecutive Caucasian hypertensive never-treated outpatients (160 men and 140 women, aged 52.9 ± 9.2 years). Subjects underwent OGTT and measurements of 25(OH)D and standard laboratory tests. Estimated glomerular filtration rate (e-GFR) was calculated by CKD-EPI formula and insulin sensitivity was assessed by Matsuda-index.

Results: Among participants, 230 were NGT, 44 had impaired glucose tolerance (IGT) and 26 had type-2 diabetes. According to 1-h post-load plasma glucose cut-off point of 155 mg/dL, we divided NGT subjects into: NGT < 155 (n = 156) and NGT > 155 mg/dL (n = 74).NGT ≥ 155 had higher significant fasting and post-load glucose and insulin, parathyroid hormone and hs-CRP levels than NGT < 155. On the contrary, Matsuda-index, e-GFR, and 25(OH)D were significantly lower in NGT ≥ 155 than NGT < 155 subjects. In the multiple regression analysis, 25(OH)D levels resulted the major determinant of 1-h post-load plasma glucose in all population and in the four groups of glucose tolerance status. In the whole population, Matsuda-index, hs-CRP and e-GFR explained another 12.2%, 6.7% and 1.7% of its variation.

Conclusions: Our data demonstrate a significant and inverse relationship between 25(OH)D levels and glucose tolerance status, particularly with 1-h post-load glucose.

MeSH terms

  • Adult
  • Biomarkers / blood
  • Blood Glucose / metabolism*
  • Cohort Studies
  • Cross-Sectional Studies
  • Female
  • Glucose Tolerance Test / methods
  • Humans
  • Hypertension / blood*
  • Hypertension / diagnosis*
  • Male
  • Middle Aged
  • Time Factors
  • Vitamin D / blood*

Substances

  • Biomarkers
  • Blood Glucose
  • Vitamin D