Lifestyle Changes Save Older Overweight People

Summarized by Robert W. Griffith, MD
February 19, 2007

Summary

A randomized controlled study shows that lifestyle intervention (diet and exercise, supported by group behavioral therapy) significantly decreases multiple cardiovascular risk factors in obese elderly people.

Introduction

Coronary heart disease is still a major cause of death, in spite of all the recent advances in prevention and treatment. It's more common with advancing age and obesity. Lifestyle changes, even if begun late in life, can certainly improve the situation, but controversy remains as to whether weight loss is a benefit in the elderly. Many old people are frail, and further weight loss would appear to be detrimental. Mortality associated with obesity decreases with aging, as shown by the body mass index (BMI) range linked to lowest mortality shifting upwards with age.

These considerations led Washington University researchers to determine whether lifestyle interventions improve cardiovascular risk factors in obese older people. Their findings, and the implications, are published in the American Journal of Clinical Nutrition, and summarized here.

What was done

Twenty-seven obese older men and women were enrolled in the study. Obesity was defined by a BMI of 30 or more, and the age requirement was 65 years or above. The participants could be described as mildly-to-moderately frail, as they showed at least two of the following; 1. impaired physical performance testing; 2. impaired peak oxygen consumption; and 3. difficulty in performing 2 instrumental or 1 basic activity of daily living (ADL)¹

All the participants underwent a full work-up - medical history, physical exam, labs, ECG, exercise stress test, etc. Those with severe cardiac or respiratory disease, history of diabetes or malignancy, and current hormone or steroid medication were excluded.

They were randomly assigned to 26 weeks' treatment with a low-calorie diet, exercise training, and weekly group behavioral therapy (17 subjects), or no treatment (10 subjects). Exercise training consisted of 90-minute sessions, three times a week. Diets were individualized to provide a deficit of about 750 calories a day, according to the subject's estimated energy requirements. Adjustments were made to prevent a loss of more than 1.5% of body weight per week.

The assessments made at baseline and after 26 weeks were: waist circumference, blood pressure, serum lipids, free fatty acids, serum inflammatory markers (C-reactive protein [CRP] and interleukin-6), and a glucose tolerance test. Fat mass and fat-free mass were measured by dual-energy X-ray absorptiometry. The presence of the metabolic syndrome was determined using the standard criteria (see the first link below).

What was found

Of the 27 participants, 24 successfully completed the study. Their average age was 70; 67% were women, and the average BMI was 31. At baseline, 15 of the 17 subjects in the treatment group and 9 of 10 in the control group had the metabolic syndrome - 89% overall.

After 26 weeks, the treatment group had lost 8.6% of their body weight - an average of 8.2 kg (18 pounds); the controls' body weight didn't change significantly. The frequency of metabolic syndrome in the treated subjects fell to 5 of 17 (29%), although serum high-density lipoprotein (HDL) cholesterol levels didn't change significantly.

The other significant changes after 26 weeks are shown in the table:

	Control Group	Lifestyle Group
Waist circumference	+ 1 cm	- 10 cm
Fasting glucose	+ 4 mg/dL	- 4 mg/dL
Triglycerides	0	- 45 mg/dL
Systolic blood pressure	- 2 mm Hg	- 10 mm Hg
Diastolic blood pressure	0	- 8 mm Hg
Glucose tolerance	7% deterioration	3% improvement
Insulin sensitivity index	5% improvement	66% improvement
Free fatty acids	+ 10 mmol/L	- 99 mmol/L
CRP	+ 0.8 mg/L	- 2.5 mg/L
Interleukin-6	+ 1.6 pg/mL	- 2.4 pg/mL

It can be seen that the lifestyle intervention significantly decreased multiple cardiovascular risk factors in these obese older people. There were no significant changes in HDL- and LDL-cholesterol, or liver and kidney tests.

What this means

The researchers claim this is the first randomized controlled trial that examines the effects of lifestyle intervention (diet and exercise, with support for both from group behavioral therapy) on cardiovascular risk factors in older obese individuals. They point out the economic implications of their findings - increased risk factors, which are responsible for the metabolic syndrome and increased medical care costs, could be reduced considerably if a healthy lifestyle was to be adapted by more seniors.

Combining exercise with diet has the advantage of avoiding some of the pitfalls of weight loss in the elderly - e.g. loss of muscle mass (lean body mass) and reduced bone mineral density, both of which can contribute to falls and fractures. There's no doubt that such lifestyle changes carry more benefits than disadvantages. No more excuses!

Source

• Effect of lifestyle intervention on metabolic coronary heart disease risk factors in obese adults. DT. Villareal, BV. Miller III, M. Banks,  et al., Am J Clin Nutr, 2006, vol. 84, pp. 1317--1323

Footnotes
1. ADL is a tool used to describe the functional status of a person. It is useful for assessing the elderly, the mentally ill, and those with chronic diseases. The activities list has a number of components - showering, dressing, eating, etc - but there are no strict rules. Instrumental activities of daily living (IADL) include activities not necessary for fundamental functioning, but still very useful in the community - cooking, shopping, housework, etc, are in this category.

Related Links
Do You Have the Metabolic Syndrome?
Watch Your Waist to Save Your Brain
Is Obesity More Damaging Than Inactivity?

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