Since we began this web site we have espoused the fact that weight control is one of the three prongs of diabetes treatment. To this end we would like to share with you a recap of a most interesting article which appeared in the Dec. 8, 1999 JAMA titled A prospective study of weight change and health-related quality of life in women, by Fine, J. T., ScD et al. Last month we shared with you the worrisome information about the rise in mean body weight of US adults in the last 15 years. We also shared the physical results of what this means to us in terms of illnesses. This article examines the association between weight change and health-related quality of life, a topic that is pertinent to our readers whether male or female.You will recall that this article was deemed important enough to make the early morning talk shows including the Today Show.
The participants in this study were from the Nurses Health Study, a four year prospective study from 1992 to 1996 when 121,700 registered female nurses aged 30 through 55 years of age completed a mailed questionnaire about risk factors for cancer and cardiovascular disease. Since then, follow-up questionnaires have been mailed every 2 years on a variety of health related risk factors including body weight and occurrences of major illnesses. A follow-up rate of higher than 90% has been maintained for the 20-year period.
BMI data were calculated from height taken from the 1976 baseline questionnaire and from weight as reported on the 1992 questionnaire. Validity of weight reporting was established when 184 women were weighed by technicians 6 to 12 months after completing the questionnaire.
Weight losers were defined as women who lost 2.25 kg ( 5 pounds) or more between 1992 and 1996 and did not gain 2.25 kg (5 lb.) or more during either 2-year intervals. These were further divided into 2 groups: those who lost between 2.25 kg and 9.0 kg (5-20 lb.) and those who lost more than 9.0 kg ( 20 lb.). Weight gainers were defined as women who gained 2.25 kg (5 lb.) or more in either 2 year interval. They were further divided into 2 groups: those who gained between 2.25 -9.0 kg, and those who gained more than 9.0 kg (20 lb.). Weight Maintainers were defined as women whose weight was within 2.25kg (5 lb.) of their original weight in 1992 and who did not gain or lose more than 2.25 kg (5 lb.) during the 2 year intervals.
Covariants, those confounders that can make results unreliable and not replicable were accounted for. These included age, cigarette smoking, levels of physical activity, alcohol consumption and self reported comorbid conditions such as diabetes, hypertension, hypercholesterolemia, rheumatoid arthritis, and osteoarthritis.
Lest you think there were not many participants, the final sample consisted of 45,375 women ( from 46-71 years of age in 1992) classified as weight losers, 7523; weight gainers, 16,983; and weight maintainers, 15,602; as well as 5277 women whose pattern of weight change did not fit one of the three categories (weight fluctuators were not analyzed further in the study).
Now comes the results that made many stand up and take notice. First in the women younger than 65 years, weight gain was associated with decreased functioning in every BMI category. With between 5-11 point score decrements, the most dramatic reductions were apparent on scales of physical vitality and bodily pain among women who gained 9.0 kg (20 lb.) or more over a 4-year period. Also weight gain of 9.0kg (20 lb.) or more was associated with about a 2 point reduction in mental health score among women whose BMI was higher then 25.0kg/m2. Women who gained weight experienced increased risks of role limitation due to physical and emotional problems as compared with women who maintained their weight. Except for women in the lowest BMI category (<25.0 kg/m2), weight loss was associated with improved vitality and to a lesser extent, improved physical function and bodily pain score. Weight loss in heavier women was not associated with improved odds of emotional or physical functioning. With women in the lowest BMI (< 25.0kg/m2 ), the weight loss was associated with a 4 year deterioration in mental health scores. This group was very small (n=51) in the older group and n=44 for the younger group. It was concluded that weight loss was involuntary, due to an underlying physical or mental illness.
In women older than 65, associations between weight gain and quality of life were similar to those observed in younger women. Weight gain, especially of 9.0 kg (20 lb. or more) were associated with decreased physical functioning, vitality, and freedom of bodily pain regardless of baseline BMI. This weight gain was also associated with increased odds of role limitations due to physical problems, however, weight gain was not associated with change in mental health in older women. Weight loss was associated in improvements in physical functioning among women in the 2 highest BMI categories. However, weight loss was associated with decreased physical function, vitality, mental health, and increased bodily pain among the leanest women. Again the researchers associated this to underlying physical or emotional illness.
Let's sum this up because the significance of this research is important to us as adults and as parents. Weight gain, as little as 5 pounds, was consistently associated with declines in physical functioning and vitality, as well as increased bodily pain. Conversely, weight loss, again as little as 5 pounds, was associated with improved physical functioning and decreased bodily pain among women in the 2 heaviest BMI categories. These associations between weight gain and loss of function were just as strong among older women as among younger women. Weight change was more strongly associated with physical than mental components of health-related quality of life. In terms of clinical significance, the researchers found the average decline in physical function of 6.9 points experienced by younger women who gained 9.0 kg (20 kg) or more over 4 years (compared with women who maintained their weight) was nearly 3 times the magnitude of the decline in physical functioning associated with cigarette smoking over the same period.
One limitation of this study was the lack of availability of information describing whether or not weight loss was intentional. It was not always possible to establish the direction of causality or to rule out the possibility that depression or some underlying illness caused weight change. The number of these women was small as stated before, but was especially note worthy in the older leanest women who lost large amounts of weight and simultaneously experienced declining health status.
In conclusion, the researchers in a longitudinal study found a strong association between weight change (again as little as 5 pounds) and change in health-related quality of life among normal weight and over-weight middle aged women. Their findings support current US guidelines for women of all BMI levels to avoid weight gain during adulthood. It also supports the fact that we espouse here at diabetic-lifestyle.com: that overweight women who lose weight can substantially improve physical function.
