Low-carbohydrate diet and cardiovascular diseases in Iranian population: Tehran Lipid and Glucose Study

Studies indicated that the risk of cardiovascular disease (CVD) in association to greater adherence to low-carbohydrate diet (LCD) differs in various populations. In this study, we aimed to assess the association of LCD score with the risk of CVD events in a prospective population-based study.

CVD-free participants (n = 2188) were recruited from the Tehran Lipid and Glucose Study (2006-2008) and followed for a mean of 6.7 years. Using a valid and reliable 168 item semi-quantitative food frequency questionnaire, the LCD score was determined based on the percentage of energy as carbohydrate, protein, and fat, which ranged from 0 to 12. Cox proportional hazard regression models, adjusted for potential confounders, were used to estimate the hazard ratios (HRs) and 95% confidence interval (CI) of CVD across tertiles of LCD score in women and men. Mean ± SD age of participants (44.8% male) was 38.8 ± 13.0 years, and median (25-75, interquartile range) of the LCD score was 6 (4-8) at baseline. During follow-up, 77 (3.5%) new cases of CVD were identified. After adjustment for sex, age, body mass index, physical activity, smoking, energy intake, diabetes, and hypertension, there was no association between the LCD score and risk of CVD outcomes in all participants (HR = 0.93; 95% CI: 0.86-1.02) and women (HR = 1.13; 95% CI: 0.94-1.36); however, the LCD score was associated with an 11% reduced incidence of CVD events in men (HR = 0.89; 95% CI: 0.80-0.98), (P for trend: 0.028).

Findings showed that higher adherence to LCD may be associated with a lower risk of CVD outcomes in men but not in women.