Disease Control Bulletin: December 1999

Contents

disease control bulletin

Volume 1, Issue 6, 1999

Overweight and Obesity

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Vermont, Overweight Adults by Gender (BMI of 25 or Greater)

vermont overweight adults by gender

Summary of NHLBI Overweight/Obesity Guidelines—1998

 In 1998, the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health published evidence-based clinical guidelines for the identification, evaluation and treatment of overweight and obesity in adults. The Guidelines and resultant report were the culmination of an expert panel’s review of the scientific literature. This was the most extensive obesity research review to date. The recommended classification, BMI (bodymass index), calculated as weight in kilograms divided by the square of the height in meters, is similar to the categories used by the World Health Organization and consistent with the US Department of Agriculture’s Dietary Guidelines for Americans overweight and obesity recommendations.

It is well established that overweight and obesity increase health risk for many diseases. A recent analysis of national health survey data substantiates this, as BMI levels rise, average blood pressure and total cholesterol levels also increase, and average high-density lipoprotein levels decrease. People in the highest obesity category had five times the risk of hypertension, high blood cholesterol or both compared to those of normal weight. In Vermont, 5.5 percent of adults who are overweight or obese report having diabetes, compared to only 2 percent of adults of normal weight. Twenty seven percent report being told their blood pressure was high compared to 13 percent of adults of normal weight and 25 percent report having elevated cholesterol compared to 14 percent of adults of normal weight7.

Evidence from randomized controlled clinical trials demonstrates that weight loss improves many of the risk factors. Weight loss decreases elevated blood glucose in obese and overweight persons and lowers high blood pressure and high total cholesterol. A recent study, reports that small, sustained reductions (10 % of body weight) in weight loss resulted in significant health benefits and health cost savings8.

Body Mass Index

The BMI categories are based on research that links elevated BMIs with adverse health outcomes, including type 2 diabetes, hypertension, cardiovascular disease and death. Overweight is defined as a BMI of 25 to 29.9 and obesity as a BMI of 30 or above (see chart). BMI usually correlates well with total body fat. However, very muscular people may have a high BMI without excess body fat and, thus, might not be at greater health risk. Once height and weight are assessed, the BMI chart insert can be used to quickly determine BMI.

Waist Circumference

 In addition to BMI, the Guidelines recommend that health care professionals use waist circumference to assess overweight and obesity. Excess abdominal fat is an independent predictor of disease risk and waist circumference is strongly associated with abdominal fat. Waist circumference more accurately assesses abdominal fat and is a better predictor of disease risk than the waist-to-hip ratio. For men and women with a BMI in the range of 25 to 34.9,excessive waist circumference — more than 40 inches in men or 35 inches in women—increases the risk of obesity-related disease beyond the risk of the BMI alone.

Associated Risk Factors

In addition to BMI and waist circumference measures, there are several associated risk factors that should be assessed. They include elevations in blood pressure, blood cholesterol, and glucose levels, and a family history of obesity-related disease. (Refer to BMI chart insert for a complete list of risk factors recommended for evaluation.) Patients with added risk factors are considered to be at a higher risk for health problems and require more intensive therapy.

Weight Loss Strategies and Goals

Unfortunately there are no magic cures for weight loss. The most successful strategies for weight loss include reduced calorie consumption, increased physical activity and behavior therapy designed to improve eating and physical activity habits. Successful weight loss programs include all three components.

A diet that is individually planned and takes into account the patient’s current caloric intake to create a deficit of 500 to 1,000 kcal/day is recommended. Although increased physical activity will not contribute to substantially greater weight loss, it is critical for the prevention of weight regain. In addition, exercise reduces cardiovascular and diabetes risk beyond it’s effect on weight.

For obese patients, exercise should be initiated slowly, and the intensity increased gradually. The patient can start by walking slowly for 10 - 30 minutes 3 days a week, building to 45 minutes of more intense walking at least 5 days a week.

Behavior therapy is based on learning principles such as reinforcement, that provide tools for overcoming barriers to compliance with dietary change and increased exercise. Research has demonstrated the effectiveness of behavior therapy in both weight loss and maintenance. Specific strategies include self-monitoring of eating habits, food intake, and physical activity; stress management; stimulus control; problem solving; contingency management; cognitive restructuring; and social support.

The Guidelines recommend weight loss for persons with a BMI of 30 or more. Weight loss is also recommended for those with a BMI between 25 and 29.9 or who have a waist circumference greater than 40 inches in a man and 35 inches in women, and who have two or more risk factors. An overweight person with a BMI between 25 and 29.9 who has fewer than two risk factors should prevent further weight gain.

The initial treatment goal is the reduction of about 10 percent of body weight. Setting more ambitious goals should be avoided to allow the opportunity for success. Patients should be advised to try to lose weight for at least six months. After six months of weight loss treatment, efforts to maintain weight loss should be put into place. It is important to note that weight is usually regained unless a weight maintenance program consisting of dietary therapy, physical activity, and behavior therapy is continued indefinitely.

In carefully selected patients, appropriate drugs can enhance the effect of low calorie diets, physical activity and behavior therapy on weight loss. Weight loss surgery is an option for weight reduction in a limited number of patients with clinically severe obesity, (i.e.,BMIs>40or>35withcomorbidconditions). Weight loss surgery should be reserved for patients for which weight management and drug therapies have failed, and who are suffering from the complications of extreme obesity.

Exercise: How Are We Doing?

 Regular exercise ,(defined as some type of exercise for at least 30 minutes five or more times a week), can help maintain weight, however, only 25 percent of Vermont adults get regular exercise. And an even lower percentage of overweight adults (22%)and obese adults (18%) exercise regularly3. In Vermont, 34 to 35 percent of physicians routinely (defined as with 80% or more patients) advise patients about developing an exercise plan9. Clearly this is a missed opportunity, as research demonstrates patients counseled by physicians increase physical activity more readily.

Counseling the Overweight and Obese

According to a recent study, people receiving advice to lose weight were significantly more likely to report trying to lose weight than those who reported not being advised 10. This concurs with other physician counseling research. Unfortunately only half of obese adults report being advised to lose weight by health professionals—another missed opportunity.

“KnowYourBMI”

The guidelines recommend that BMI be determined for all adults. For those categorized as overweight or obese further assessment and treatment is recommended. Those of normal weight should have their BMI reassessed in two years. Everyone should know their BMI and what it means.

Overweight/ObesityWorkingGroup

The Vermont Department of Health recently hosted an adult obesity strategic planning meeting. As a result of this meeting the Health Department will form a working group to address this issue.

If you are interested in participating in the Obesity Working Group or would like patient materials, please contact Alison Gardner, (802) 865-7705, e-mail: <agardne@vdh.state.vt.us>. Additional copies of the BMI chart, a pamphlet for patient education, “Do You Know the Health Risks of Being Overweight?”,and a flyer on"Physical Activity: Getting Started" are also available.

A copy of the NIH report “Clinical Guidelines on the Identification, Evaluation ,and Treatment of Overweight and Obesity in Adults” 1998 can be downloaded from the NHLBI at URL <www.nhlbi.nih.gov>or ordered by calling(301)592-8563.

References:

  1. Allison DB, Fontaine KR, Manson JE, Stevens J, VanItallie TB. Annual Deaths Attributable to Obesity in the U.S. JAMA 1999;282:1530-1538.
  2. National Institutes of Health, National Heart, Lung and Blood Institute. Clinical Guidelines on the Identification, Evaluation and Treatment of Overweight and Obesity in Adults: The Evidence Report. 1998.
  3. Vt. Department of Health. Vermont Health Plan. 1999.
  4. Colditz GA. The Nurse’s Health Study: Findings During 10 years of Follow-up of a Cohort of U.S. Women. Curr Probl Obstet Gynecol Fertil 1990;13:131.
  5. Manson JE, Willett WC, Stampfer MJ et al. Body Weight and Mortality Among Women. N Engl J Med 1995;333:677.
  6. Wolf AM, Colditz GA. Current Estimates of the Economic Costs of Obesity in the U.S. Obesity Res 1998;6:97-106.
  7. Vt. Department of Health. Behavior Risk Factor Surveillance Survey. 1996-1998.
  8. Oster G, Thompson D, Edelsberg J, Bird A, Colditz G. Lifetime Health and Economic Benefits and Weight Loss Among Obese Persons. Am J Public Health 1999;89:1536-1542.
  9. Vt. Department of Health. Vt. Primary Care Preventive Practices Survey, 1996.
  10. Galuska DA, Will JC, Serdula MK, Ford ES. Are Health Care professionals Advising Obese Patients to Lose Weight? JAMA 1999; 282:1576-1578.

Body Mass Index Chart

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Impact of Multiple Births on Low Birthweight Vermont, 1990-1998

The low birthweight rate has been increasing throughout the 1990’s, both nationally and in New England. A recent study in Massachusetts (MMWR, April 16, 1999) examined the impact of plurality distribution on the low birthweight rate in that state.

The low birth weight rate among singleton births was in fact stable (5.9%) for the period of the Massachusetts study (1989-1996), while the low birthweight rate for twins increased only slightly. The conclusion was that the increasing proportion of multiple births was responsible for the overall increase in the low birthweight rate, as there were no significant changes in plurality specific low birthweight rates. Vermont is also experiencing a steady increase in the low birthweight rate, however there has not been a significant increase in the proportion of multiple births, and there is no significant impact of the plurality distribution on the low birthweight rate in Vermont.

Vermont resident births from 1990 to 1998 were examined,and plurality adjusted low birthweight rates were calculated by applying plurality specific low birthweight rates to the 1990 plurality distribution. That is, the adjusted low birthweight rate is the rate we could expect to see if each subsequent year had the same plurality distribution as 1990. The table below indicates that there is very little difference in the unadjusted and adjusted low birthweight rates, as might be expected since there is relatively little variation in the plurality distribution.

The 1998 figures do mark an increase in the proportion of multiple births, and the difference between the unadjusted and adjusted low birthweight rates is larger for 1998 than any other year. This change in the plurality distribution does appear to explain the increase in low birthweight from 1997 to 1998, but the low birthweight increase seen in earlier years cannot be attributed to changes in the proportion of multiple births. Continued surveillance of these data will take place to assess the impact of plurality distribution on Vermont’s low birthweight rate in the future.

Number of births and percentage distribution of births and low birthweight (LBW) infants, by plurality, and unadjusted and adjusted LBW rates* - Vermont, 1990-1998
Singletons Twins Triplets-plus Multiple Unadjusted Adjusted##
Year Births^ % of births % LBW % of births % LBW % of births % LBW % of births LBW rate LBW rate
1990 8264 97.48% 4.53% 2.48% 36.10% 0.04% 66.67% 2.52% 5.34% 5.34%
1991 7935 97.86% 4.76% 2.07% 46.34% 0.08% 83.33% 2.14% 5.68% 5.82%
1992 7708 97.56% 4.52% 2.44% 48.40% 0.00% 0.00% 2.44% 5.59% 5.61%
1993 7438 97.08% 4.36% 2.84% 50.24% 0.08% 66.67% 2.92% 5.71% 5.52%
1994 7382 97.39% 4.67% 2.44% 55.00% 0.18% 92.31% 2.61% 6.06% 5.95%
1995 6777 97.89% 4.54% 2.11% 46.15% 0.00% 0.00% 2.11% 5.42% 5.57%
1996 6737 97.51% 5.18% 2.45% 45.45% 0.04% 100.00% 2.49% 6.20% 6.21%
1997 6581 97.95% 5.13% 1.98% 58.46% 0.08% 100.00% 2.05% 6.26% 6.49%
1998 6562 96.75% 5.06% 3.25% 52.58% 0.00% 0.00% 3.25% 6.60% 6.23%

* per 100 live births.

^ Records for which plurality or birthweight was unknown are excluded.

## LBW rate adjusted to 1990 plurality distribution.

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Physicians and Midwives Responsible for Birth Certificates

Today, hospitals file birth certificates as a service to their physicians. However, it remains the responsibility of the physician or midwife to provide complete information and meet the 10 day deadline.

Some physicians and midwives may not be aware of a law that makes them responsible for filing birth certificates. Section 5071 of Title 18, Vermont Statutes, reads:

(a) Unless a physician or midwife is present, the head of the family in which a birth occurs, within 10 days thereafter, shall fill out and file with the town clerk a certificate of birth in the form prescribed by the [health] department. Otherwise the certificate shall be filed by the attendant physician or midwife.

A $5 penalty for failure to comply with this statute still exists in Vermont law (dating back to 1862). Although the $5 penalty may seem minuscule today, the very existence of a penalty means that someone bringing suit against a physician or midwife who failed to meet the deadline would not have to prove a breach of duty in order to collect damages.

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Selected Reportable Diseases Vermont,
Year to Date (12/04/99)

reportable diseases dec 1999

YTD=YeartoDateTotal

No 5-year median available: Cryptosporidiosis; E. coli O157:H7; Group A Strep, Invasive; Acute Hepatitis C

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ACIP Modifies Recommendations for Meningitis Vaccination

The Advisory Committee on Immunization Practices (ACIP) has modified its guidelines for use of the polysaccharide meningococcal vaccine to prevent bacterial meningitis, particularly for college freshmen who live in dormitories, a group found to be at modestly increased risk of meningococca ldisease relative to other persons their age.

At its October 20, 1999 meeting, the ACIP, citing results of two CDC studies done in 1998 which identified the slightly higher risk among freshmen dormitory residents, recommended that those who provide medical care to this group give information to students and their parents about the benefits of vaccination. Vaccination should be provided or made easily available to those freshmen who wish to reduce their risk of disease. Other undergraduate students wishing to reduce their risk of meningococcal disease can also choose to be vaccinated.

The currently available vaccine protects against some serogroups of the bacterium Neisseria meningitidis, an important cause of bacterial meningitis and sepsis. A single dose of the vaccine is recommended, and vaccination will decrease the risk of disease caused by N. meningitidisserogroups A , C, Y and W-135. However, vaccination will not totally eliminate the risk of the disease because the vaccine does not protect against serogroup B and because, although it is highly effective against serogroups C and Y, it still does not confer 100 percent protection against the seserogroups. In 1998-1999, serogroups C and Y caused about 70 percent of cases among college students.

Approximately 3,000 cases of meningococcal disease occur each year in the United States, and 10-13 percent of patients die despite receiving antibiotics early in the illness. Among surviving, an additional 10 percent have severe aftereffects of the disease, including mental retardation, hearing loss and loss of limbs.

On September 30, 1997, the American College Health Association (ACHA), which represents about one-half of colleges with student health services in the United States, released a statement recommending that "college health services [take] a more proactive role in alerting students and their parents about the dangers of meningococcal disease" and that "college students consider vaccination against potentially fatal meningococcal disease." In early 1998, CDC initiated, in collaboration with the Council of State and Territorial Epidemiologists (CSTE) and ACHA’s Vaccine Preventable Disease Task Force, two studies to better define the risk of meningococcal disease associated with college campuses. Both studies indicated that freshmen college students, particularly those who live in dormitories, constitute a group at a modestly increased risk for meningococcal disease.

For more information, see the following websites or contact theVermont Department of Health at 1-800-640-4374or802-863-7240. The URLs are <http://www.cdc.gov/ncidod/dbmd/ diseaseinfo/meningococcal_college.htm><http://www.acha.org/ special-prj/men/faq.htm>.