10 September, 2012:
A recent paper by Kroenke and colleagues discussed the dietary intervention component of the Women's Health Initiative . The intervention was a reduction in fat intake whilst increasing that of fruit, vegetables and whole grains. The outcome was the impact of this, whether accompanied by weight loss or not, on vasomotor symptoms (VMS) in postmenopausal women. A total of 17,500 postmenopausal women aged 50–79 years were recruited into this arm, none of whom were meant to be taking menopausal hormone replacement therapy (HRT). The study found that there was a significant weight loss in the dietary intervention arm that was associated with elimination of symptoms among women who had vasomotor symptoms at baseline (odds ratio (OR) 1.14; 95% confidence interval (CI) 1.01–1.28), who lost more than 10 lbs (OR 1.23; 95% CI 1.05–1.46) or lost 10% or more of their baseline body weight (OR 1.56; 95% CI 1.21–2.02) between baseline and year 1. These groups were significantly more likely to cease having VMS, compared with those who maintained weight. Finally, women who lost substantial weight as a part of the intervention group (OR 1.89; 95% CI 1.39–2.57), but not as part of the control group (OR 1.40; 95% CI 0.92–2.13), were significantly more likely to stop having VMS. Large weight loss (> 22 lbs), but not dietary changes, was related to the elimination of moderate/severe VMS. The conclusion to the study was that weight loss, as part of healthy diet modification, may help eliminate vasomotor symptoms amongst postmenopausal women.
Women were randomized to a diet with 20% of energy derived from fat and five servings of fruit and vegetables daily as well as six of whole grain. They were, in addition, given an intensive behavioral modification program to assist them in achieving this diet. The control group received a copy of a publication 'Dietary guidelines for Americans' but had no direct contact with the nutrition interventionists. Although weight loss was not a primary end to the diet modification, 21% of the intervention group and 7% of the controls lost weight. Weight change was assessed looking at absolute values as well as a percentage change in weight to allow categorization. VMS were reported using a questionnaire assessing hot flush and night sweat occurrence and severity in the previous 4 weeks that was scored from none (0) to severe (3). A score of 1 indicated that there was no interference with the usual activities, 2 that they interfered somewhat, and 3, interfered a lot. Covariates such as demographic factors, years since hysterectomy and depressive symptoms were taken into account.
A total of 6104 women had VMS at baseline and were examined separately; 26% of women reported hot flushes at baseline with only 1% being severe, i.e. 61 women. These women, not surprisingly, were younger and more recently menopausal as one would expect and the VMS were more likely to occur in African-American women, those who were less educated, smoked and with depressive symptoms as well as lower alcohol intake. No comment was made on whether the women had taken HRT in the past or not. The intervention led to an improvement in symptoms, although it is very difficult to take account of natural history since it is known that the women with symptoms were younger and some would be expected to improve anyway. Not all VMS, particularly in older women, respond well to hormone intervention.