Plasma vitamin C modifies the association between hypertension and risk of stroke

Stroke. 2002 Jun;33(6):1568-73. doi: 10.1161/01.str.0000017220.78722.d7.

Abstract

Background and purpose: There are no prospective studies to determine whether plasma vitamin C modifies the risk of stroke among hypertensive and overweight individuals. We sought to examine whether plasma vitamin C modifies the association between overweight and hypertension and the risk of stroke in middle-aged men from eastern Finland.

Methods: We conducted a 10.4-year prospective population-based cohort study of 2419 randomly selected middle-aged men (42 to 60 years) with no history of stroke at baseline examination. A total of 120 men developed a stroke, of which 96 were ischemic and 24 hemorrhagic strokes.

Results: Men with the lowest levels of plasma vitamin C (<28.4 micromol/L, lowest quarter) had a 2.4-fold (95% CI, 1.4 to 4.3; P=0.002) risk of any stroke compared with men with highest levels of plasma vitamin C (>64.96 micromol/L, highest quarter) after adjustment for age and examination months. An additional adjustment for body mass index, systolic blood pressure, smoking, alcohol consumption, serum total cholesterol, diabetes, and exercise-induced myocardial ischemia attenuated the association marginally (relative risk, 2.1; 95% CI, 1.2 to 3.8; P=0.01). Adjustment for prevalent coronary heart disease and atrial fibrillation did not attenuate the association any further. Furthermore, hypertensive men with the lowest vitamin C levels (<28.4 micromol/L) had a 2.6-fold risk (95% CI, 1.52 to 4.48; P<0.001), and overweight men (> or =25 kg/m2) with low plasma vitamin C had a 2.7-fold risk (95% CI, 1.48 to 4.90; P=0.001) for any stroke after adjustment for age, examination months, and other risk factors.

Conclusions: Low plasma vitamin C was associated with increased risk of stroke, especially among hypertensive and overweight men.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Ascorbic Acid / blood*
  • Body Mass Index
  • Brain Ischemia / blood
  • Brain Ischemia / epidemiology
  • Cerebral Hemorrhage / blood
  • Cerebral Hemorrhage / epidemiology
  • Cohort Studies
  • Demography
  • Finland / epidemiology
  • Follow-Up Studies
  • Humans
  • Hypertension / blood*
  • Hypertension / epidemiology
  • Male
  • Middle Aged
  • Obesity / blood
  • Obesity / epidemiology
  • Prospective Studies
  • Risk
  • Risk Assessment
  • Risk Factors
  • Stroke / blood*
  • Stroke / epidemiology

Substances

  • Ascorbic Acid