A prospective study of fasting plasma glucose and risk of stroke in asymptomatic men

To examine the association between levels of fasting plasma glucose (FPG) and incidence of stroke outcomes in a large cohort of asymptomatic men.

Participants were 43,933 men (mean ± SD age, 44.3 ± 9.9 years) who were free of known cardiovascular disease at baseline and whose FPG levels were assessed during a preventive medical examination at the Cooper Clinic, Dallas, TX, between January 7, 1971, and March 11, 2002. Patients with diagnosed diabetes mellitus (DM) or low FPG (<80 mg/dL [to convert to mmol/L, multiply by 0.0555]) were excluded. Fatal stroke was identified through the National Death Index, and nonfatal stroke was ascertained from mail-back surveys.

A total of 595 stroke events (156 fatal and 456 nonfatal strokes; 17 men reported a nonfatal stroke before they died of stroke) occurred during 702,928 person-years of exposure. Age-adjusted fatal, nonfatal, and total stroke event rates per 10,000 person-years for normal FPG (80-109 mg/dL), impaired fasting glucose (110-125 mg/dL), and undiagnosed DM (≥ 126 mg/dL) were 2.1, 3.4, and 4.0 (P(trend)=.002); 10.3, 11.8, and 18.0 (P(trend)=.008); and 8.2, 9.6, and 12.4 (P(trend)=.008), respectively. After further adjusting for potential confounders, the direct association between FPG and fatal, nonfatal, or total stroke events remained significant (P(trend)=.02, .03, and .01, respectively). For FPG levels of 110 mg/dL or greater, each 10-unit increment of FPG was associated with a 6% higher risk of total stroke events (P=.05).

Hyperglycemia (FPG, ≥ 110 mg/dL), even below the DM threshold (such as with impaired fasting glucose), was associated with a higher risk of fatal, nonfatal, or total stroke events in asymptomatic men.