Dietary fats, carbohydrate, and progression of coronary atherosclerosis in postmenopausal women

Abstract

Background: The influence of diet on atherosclerotic progression is not well established, particularly in postmenopausal women, in whom risk factors for progression may differ from those for men.

Objective: The objective was to investigate associations between dietary macronutrients and progression of coronary atherosclerosis among postmenopausal women.

Design: Quantitative coronary angiography was performed at baseline and after a mean follow-up of 3.1 y in 2243 coronary segments in 235 postmenopausal women with established coronary heart disease. Usual dietary intake was assessed at baseline.

Results: The mean (+/-SD) total fat intake was 25 +/- 6% of energy. In multivariate analyses, a higher saturated fat intake was associated with a smaller decline in mean minimal coronary diameter (P = 0.001) and less progression of coronary stenosis (P = 0.002) during follow-up. Compared with a 0.22-mm decline in the lowest quartile of intake, there was a 0.10-mm decline in the second quartile (P = 0.002), a 0.07-mm decline in the third quartile (P = 0.002), and no decline in the fourth quartile (P < 0.001); P for trend = 0.001. This inverse association was more pronounced among women with lower monounsaturated fat (P for interaction = 0.04) and higher carbohydrate (P for interaction = 0.004) intakes and possibly lower total fat intake (P for interaction = 0.09). Carbohydrate intake was positively associated with atherosclerotic progression (P = 0.001), particularly when the glycemic index was high. Polyunsaturated fat intake was positively associated with progression when replacing other fats (P = 0.04) but not when replacing carbohydrate or protein. Monounsaturated and total fat intakes were not associated with progression.

Conclusions: In postmenopausal women with relatively low total fat intake, a greater saturated fat intake is associated with less progression of coronary atherosclerosis, whereas carbohydrate intake is associated with a greater progression.

FIGURE 1

Mean (±SE) change in minimal coronary artery diameter according to intake of different nutrients, with adjustments as in Table 2 (see footnote 1), except that total fat was not adjusted for carbohydrate, and carbohydrate and protein were also adjusted for polyunsaturated fat. These models estimate the effect of saturated fat replacing other fats (monounsaturated or polyunsaturated), monounsaturated fat replacing other fats (saturated or polyunsaturated), polyunsaturated fat replacing other fats (saturated or monounsaturated), total fat replacing carbohydrate, carbohydrate replacing saturated or monounsaturated fat, and protein replacing saturated or monounsaturated fat. Median intakes (% of energy) for quartiles 1-4 were as follows: saturated fat (6.1, 7.8, 9.5, and 12.0), monounsaturated fat (6.9, 8.6, 10.7, and 13.0), polyunsaturated fat (3.9, 5.2, 6.1, and 7.5), total fat (17.6, 21.7, 27.0, and 31.9), carbohydrate (47.1, 55.6, 60.5, and 68.9), and protein (12.7, 15.8, 18.0, and 21.2). P for trend = 0.001 (saturated fat), 0.40 (monounsaturated fat), 0.04 (polyunsaturated fat), 0.48 (total fat), 0.20 (protein), and 0.001 (carbohydrate).