Over and over again we have stressed the importance of diet, medication and exercise to control diabetes and yet we continue to read and hear about the increasing epidemic of obesity and diabetes in the US. This month we put our "money where our mouth is" by giving you the latest information on these problems.
The October 27th Journal of the American Medical Association is all about obesity, its implications for the health of the US and how to control weight. The spread of obesity has become an epidemic in the United States and so the topic of the month is this subject. You who have been with us know our position that we must be the most informed consumers of medical care so we offer you this new information to help you and your family and friends. It's never too late to change old habits or to help others.
Although attempts to lose weight are common in the US, the prevalence of obesity has increased since the 1980s. Recent estimates suggest that obesity-related morbidity may account for 6.8% of US health costs. Recently published trend data form the National Health and Nutrition Examination Surveys show the percentage of obese persons has increased form 14.5% in the years 1976-1980 to 22.5% in 1988-1994. A study done by Mokdad, A.H., Ph.D. et al looked at changes in the prevalence of obesity from 1991-1998. They designed a cross-sectional random-digit telephone survey (Behavioral Risk Factor Survey System) of noninstitutional adults ages 18 years or older conducted by the Centers for Disease Control and Prevention and state health departments from 1991 to 1998.
The results of the study indicate that the prevalence of obesity increased from 12.0% in 1991 to 17.9% in 1998. Obesity increased in men and women and across all socioeconomic groups with the highest increase among the youngest ages and higher education levels. In 1991, 4 of the 45 participating states had obesity rates of 15% or higher. by 1998; 37 states had rates higher than 15%. The magnitude of the increase varied by region (ranging from 31.9% to 67.2% in the mid-Atlantic and South Atlantic regions, respectively), and state by-state, ranging from 11.3% in Delaware to 101.8% in Georgia. In 1991, the level of leisure-time physical activity was 29.7% inactive, 28.4% irregular active, 33.2% regular, not intense, and 8.7% regular intense. In 1998, they were 28.6% inactive, 28.2% irregularly inactive, 29.6% regular not intense, and 13.6% regular intense. To exclude the possibility that demographic differences accounted for the variation in obesity prevalence between states, the researchers computed the age-sex-, and race-adjusted prevalence of obesity. Although the adjusted rates were higher than the unadjusted rates, similar patterns were observed among the states and over time.
These data showed that obesity increased in every state, in both sexes , and across all age groups, races, educational levels, and smoking status. Since overweight participants in self-reported studies tend to underestimate their weight and all participants tend to overestimate their height, true rates of obesity are likely underestimated. Moreover, people without telephones were not surveyed through this survey, and such individuals are likely to be of lower socioeconomic status, a factor that is associated with obesity. The net effect of these limitations is that prevalence of obesity reported in the study is likely a conservative estimate. In fact, the prevalence of obesity from NHANES III (1988-1994) in which weight and height were measured by health professionals, was 22.5% in adults, more than a third higher than the rates reported in the survey.
The disease burden associated with overweight and obesity, by Must, A. Ph.D. et al in the same journal is a must to follow up the preceding report. Recent estimates suggest that 1 in 2 adults in the US is overweight or obese, defined by a body weight mass (BMI) of higher than 25 kg/m-squared, an increase of more than 25% over the last 3 decades. These dramatic increases have occurred among the 3 major racial and ethnic groups and include both sexes. Excess weight is associated with an increased incidence of cardiovascular disease, type 2 diabetes mellitus (DM), hypertension, stroke, dyslipidemia, osteoarthritis, and some cancers.
Associations of excess weight with overweight: Researchers looked at nationally representative cross-sectional survey using data form the Third Health and Nutrition Examination Survey (NHANES III), which was conducted in 2 phases from 1988 to 1994. The results indicated that 63% of men and 55% of women had a BMI of 25 or greater. A graded increase in the prevalence (PR) was observed with increasing severity of overweight and obesity for all health outcomes except coronary heart disease in men and women and high blood cholesterol level in both men and women. PRs were highest for type 2 diabetes (95%) and gall bladder disease for men and women. Prevalence ratios generally were greater in younger than older adults. The prevalence of having two or more health conditions increased with weight status category across all racial and ethnic subgroups.
In the study the researchers estimated the cross-sectional relationship between over-weight and obesity class-levels and morbidity in a contemporary, nationally representative sample of adults. It was observed that a substantial prevalence of chronic health conditions is associated with elevated BMI for both age groups and across racial and ethnic groups. Associations of weight status and health outcomes did not differ between the three major racial and ethnic groups. The PRs generally increased with increasing severity, and, for many comorbidities, the PRs were significantly elevated even for the overweight class. Because the sample is cross-sectional, the data reflect the burden of disease associated with overweight and obesity in the US population aged 25 years and older from 1988 and 1994.
Researchers observed particularly strong-cross-sectional associations for overweight and obesity with type 2 diabetes mellitus and hypertension consistent with the findings of several large cohort studies based on nonrepresentative populations. Furthermore, they found a significant increase in PRs of both of these conditions even among persons in the overweight class. This finding is striking given that individuals with the mildest degree of overweight comprise more than 42% of men and 28% of women in the US. For the majority of health conditions studied, based on overweight status and age, PRs are increased. The analysis incorporates the newly adopted definitions of over-weight and obesity. The previous BMI cutoff points of 17.8 (men) and 17.3 (women) kg/m2 were based on a purely statistical definition (85th percentile from NHANES II). The new cutoff point of 25 kg/m2 is based on research evidence that links an elevated BMI with adverse health consequences, including type 2 diabetes mellitus, hypertension, cardiovascular disease, and death.
The influence of age on the relationship of BMI to morbidity has been the subject of some debate, especially in prospective studies. For both hypertension and CHD the relative risk associated with overweight declines with age. These researchers observed that the cross-sectional relationship of obesity class to the comorbidities studied was generally strongest among the younger age groups. Nevertheless, the PRs were significantly elevated on the older age groups except for gallbladder disease in men and high cholesterol in both sexes.
In conclusion, these national data suggest that clinicians are likely to encounter morbidity more frequently among their patients with elevated BMI, even those patients in the overweight category. A general pattern of increasing prevalence with increasing severity of overweight and obesity is consistent across racial and ethnic groups for all health conditions considered with the exception of high blood cholesterol. Without concerted initiatives to prevent and treat overweight in adults, the health care system will increasingly be overwhelmed with individuals who require treatment for obesity-related health conditions.
To underscore the importance of this research the newspapers reported (Nov. 9, 1999) on a new paper presented in Atlanta which examined how women can reduce their risk of cardiovascular disease, The landmark Nurses' Health Study conducted at the Harvard School of Public Health was reported at the meeting of the American Heart Association. It showed that women who did everything right can reduce their chance of heart disease by 82 percent. What is this everything right? It is what we espouse here on diabetic-lifestyle.com: exercise, eat right, lose weight if you are overweight, and don't smoke. Easy to say, sometimes hard to do but decreasing your risk of heart disease is worth the trouble. We urge you to read the JAMA articles we presented, plus the remainder of that journal, and learn how these new studies can point you to better health.
