Low-fat dietary pattern affects CVD risk in postmenopausal women
A shift to a low-fat diet appears to influence the risk of cardiovascular disease (CVD) in postmenopausal women, and this includes both coronary heart disease (CHD) benefit and stroke risk among healthy women, a recent study suggests.
A total of 48,835 postmenopausal women (aged 50 to 79 years) were randomized to a low-fat dietary pattern intervention (40 percent; target of 20 percent of energy from fat) and to a usual diet comparison group (60 percent).
The intervention period lasted 8.3 years, ending in March 2005. More than 80 percent of surviving participants consented to additional active follow-up through September 2010, and all women were followed for mortality through 2013. The primary outcomes were breast and colorectal cancer. Additional designated outcomes were CHD and overall CVD.
There was no between-group difference in terms of incidence rates for CHD and total CVD in either the intervention or postintervention period, but CHD hazard ratios (HRs) comparing these groups strongly differed with baseline CVD and hypertension status.
The intervention period CHD HR of participants without prior CVD were 0.70 (95 percent CI, 0.56 to 0.87) if they were normotensive or 1.04 (0.90 to 1.19) if they were hypertensive (p=0.003 for interaction). The increase in ischaemic stroke risk partially offset the CHD benefit in healthy normotensive women. In the postintervention period, corresponding HRs were close to null.
Participants with CVD at baseline (3.4 percent) had CHD HRs of 1.47 (1.12 to 1.93) in the intervention period and 1.61 (1.02 to 2.55) in the postintervention period. However, postrandomization use of cholesterol-lowering medications confounded the results in women with CVD or hypertension at baseline based on various lines of evidence, according to researchers.
The findings thus confirm that a change to a low-fat dietary pattern affects the cardiovascular health of postmenopausal women.