Associations of low carbohydrate diet score with blood pressure levels and hypertension among middle-aged Japanese: the Toon Health Study.

Hypertension is one of the major risk factors for cardiovascular diseases. However, limited evidence exists to explain the association between low-carbohydrate diet (LCD) scores and hypertension. This cross-sectional study examined the association between LCD scores and hypertension among the Japanese population, which was conducted among 2032 men and women aged 30-79 years. We measured systolic and diastolic blood pressure levels, inquired about taking antihypertensive medication, and defined hypertension and isolated systolic hypertension (ISH). Dietary intake was measured through a food frequency questionnaire, and LCD scores (total, animal-based, and plant-based) were calculated. Higher total LCD scores tended to be associated with lower multivariable means of SBP (p for trend = 0.06), and higher animal-based LCD scores also tended to be associated with lower multivariable means of SBP (p for trend = 0.06). Higher animal-based LCD scores tended to be negatively associated with hypertension; the multivariable OR (95% confidence intervals: CIs) for hypertension in the highest quintile of animal-based LCD score was 0.77 (0.48-1.21, p for trend = 0.19), and higher total LCD scores tended to be negatively associated with ISH; multivariable-adjusted OR and 95% CIs of the highest score was 0.55 (0.31-0.99, p for trend = 0.11). However, we did not find any significant associations between total and plant-based LCD scores and hypertension. Although the association did not reach the level of significance, in conclusion, the high LCD scores, especially total and animal-based LCD scores, tended to be negatively associated with hypertension and ISH in the Japanese population.