Baseline characteristics and unadjusted associations with incident CHD events (n = 2193; number of CHD events = 351).

Abbreviations: SD: standard deviation; HR: hazard ratio; CI: confidence interval; HDL: high-density lipoprotein; LDL: low-density lipoprotein; GFR: glomerular filtration rate.
*p for trend.
†Physical activity was assessed by questionnaire about all types of walking and exercise performed in the prior week [14].
‡Defined by self-report of hypertension and use of anti-hypertensive medications, or measured SBP≥140 and/or DBP≥90 mmHg.
∥Expressed as median (25%–75%), because of skewed distribution. The effect of the logarithm of the covariates on the CHD is measured.
¶Classes of CHD risk at 10 years, according to Framingham functions [2].
#Glomerular filtration rate (GFR) was estimated using the MDRD equation: GFR = 175 * Creatinine−1.154 * Age−0.203 * (1.212*Iblack+Iwhite)* (0.742*Ifemale+Imen) [32].
**Quartiles were used instead of clinical cut-offs to avoid categories with few participants. In particular, categories of GFR<15 and within 15–29.99 were collapsed with the category 30–59.99 (only 0.2% in the class of GFR<15 and 0.5% in the class of GFR within 15–29.99) and a ≥80 category was replaced to the usual ≥90 (only 7% for GFR≥90).