A new US study found that overweight and obese menopausal women who lost weight during an intensive diet and exercise program suffered fewer and less severe hot flushes compared to women who did not do the program.

You can read about the study led by researchers at the University of California San Francisco (UCSF) online in the Archives of Internal Medicine, where it appeared on 12 July.

Hot flushes, also called hot flashes, are the most common complaint among women going through the menopause, and are often linked to sleeping problems, depression and anxiety.

Lead author Dr Alison J Huang told the press that:

“We still don’t understand the underlying mechanism of hot flashes, or why some women experience flashes and others don’t.”

The researchers said up to one third of women can still be getting hot flushes five years or more past the menopause, and while studies have shown they tend to be more severe in women with higher BMI (body mass index, a measure of obesity that equals weight in kilos divided by height in metres squared), the effect of weight loss is unclear.

Estimates from the US Centers for Disease Control and Prevention (CDC) suggest nearly two thirds of women in the US are overweight (BMI between 25 and 29.9) and one third are obese (BMI of 30 or more).

Huang, who is assistant professor of internal medicine in the UCSF Department of Medicine, said their finding is good news for “millions of women who are overweight and troubled by hot flashes”, in that they may be “able to reduce their discomfort through diet and exercise”.

Senior author Dr Deborah Grady, of the UCSF Department of Medicine and the Veterans Affairs Medical Center, San Francisco, said women in the intensive weight loss group were twice as likely to see an improvement in hot flushes compared to controls.

“This gives women who suffer from hot flashes an added option in controlling their symptoms, while also creating a healthier life for themselves”, she added.

The study was an offshoot (ancillary study) of a study coordinated by UCSF called the Program to Reduce Incontinence by Diet and Exercise (PRIDE), a randomized, controlled trial to examine the effect of an intensive weight loss and exercise program in overweight and obese women with urinary incontinence.

For the study, the researchers randomly assigned 338 women aged 30 or more, with a BMI between 35 and 50 and urinary incontinence, to one of two groups. The first group (226 participants, the “intervention group”) attended an “intensive behavioral weight loss program” comprising weekly one-hour group sessions taught by experts in nutrition, exercise and how to change eating habits and behavior. They were also asked to follow a reduced calorie diet and do an extra 200 minutes a week or more of exercise.

The second group (112 participants, the “controls”), attended a “structured health education program”, comprising weekly one-hour group sessions with experts who gave general advice on health promotion, weight loss, exercise and healthy eating. They were not asked to follow a diet or do extra exercise.

The researchers asked the participants to complete questionnaires at the start of the study (baseline), and then six months later, that asked them questions about their menopausal symptoms such as how often and how intense their hot flushes were. They chose their responses from a commonly used “Likert scale” that ranged from “not at all” to “extremely”.

The team also measured the women’s weight, BMI, abdominal circumference, blood pressure, and physical and mental functioning, and assessed their calorie intake and physical activity at baseline and after 6 months.

The results showed that:

  • About half the participants (154 women), were at least “slightly bothered” by hot flushes at the start of the study.
  • Among these, there was a greater reduction in bothersome hot flushes in the intervention group than in the controls (the odds ratio (OR) of improving by 1 Likert scale position was 2.25, with 95 per cent confidence interval (95%CI) ranging from 1.20 to 4.21).
  • Improvement in hot flushes was linked to weight loss (OR 1.32, 95%CI 1.08-1.61 for every 5 kg loss), reduced BMI (OR 1.17, 95%CI 1.05-1.30, for every 1.0 of reduced BMI), and reduced abdominal circumference (1.32, 1.07-1.64, for every 5 cm reduction), and the effect was slightly weaker when adjusted for potential confounders.
  • However, no such links were observed for changes in physical activity, calorie intake, blood pressure and physical and mental functioning.

The researchers concluded that:

“Among women who were overweight or obese and had bothersome hot flushes, an intensive behavioral weight loss intervention resulted in improvement in flushing relative to control.”

They acknowledged that a possible drawback of the study was the fact it only investigated menopausal women who also had incontinence, since the study was ancillary to a main study.

But they said they did not see a link between more severe incontinence and increased hot flushes, and that other studies had not linked urinary incontinence with the menopause, so they could not see any reason why their findings should not also apply to women who are not incontinent.

“An Intensive Behavioral Weight Loss Intervention and Hot Flushes in Women.”
Alison J. Huang; Leslee L. Subak; Rena Wing; Delia Smith West; Alexandra L. Hernandez; Judy Macer; Deborah Grady; for the Program to Reduce Incontinence by Diet and Exercise Investigators.
Arch Intern Med., Vol. 170 No. 13, pp 1161-1167, published online 12 July 2010
DOI:10.1001/archinternmed.2010.162

Additional source: UCSF.

Written by: Catharine Paddock, PhD