National Growth and Health Study (NGHS)
Condition: Cardiovascular Diseases; Heart Diseases; Obesity; Coronary Disease; Hypertension
MeSH terms: Cardiovascular Diseases; Heart Diseases; Coronary Disease
Study type: Observational

Summary: 
      To determine if the Black-white differences in the development of obesity in pubescent
      females were due to differences in psychosocial, socioeconomic and other environmental
      factors. Also, to determine whether differences in the development of obesity led to
      Black-white differences in other coronary heart disease risk factors, such as blood pressure
      and serum lipids.
    

Detailed description: 
      BACKGROUND:

      Although not all scientists agree that obesity is an independent risk factor for coronary
      heart disease, it may be a strong univariate predictor of coronary heart disease, and impacts
      on coronary heart disease through at least some of its relationships with other risk factors:
      positive association with blood pressure, inverse association with high density lipoprotein
      cholesterol (HDLC), positive association with triglyceride and very low density lipoprotein
      cholesterol (VLDLC), and a positive association with hyperglycemia and diabetes. A number of
      these have been shown to be major coronary heart disease risk factors. Prevention of obesity,
      or weight reduction towards desirable body weight may reduce the incidence of coronary heart
      disease and some of its risk factors. There is evidence to suggest that once obesity begins
      and/or advances in childhood, it will track into adulthood, with a reasonably high level of
      certainty. Obesity becomes progressively more difficult to treat with maturation to
      adulthood. Thus, better understanding of the pathophysiology of obesity in late childhood and
      early adolescence should, in the long-run, provide the basis for effective prevention or
      intervention programs in order to have a long-range impact upon the consequence of obesity.
      The age group 9 and 10 at entry has been selected to assure that many of the individuals are
      enrolled prior to puberty, and followed through this transition period when obesity becomes
      more apparent among Black adolescent females than among white.

      Support for this research grew out of recommendations made at the Working Conference on
      Coronary Heart Disease in Black Populations held in September 1983 and sponsored by the
      NHLBI. The group recommended this research to identify the physiological and/or behavioral
      factors which contribute to obesity in Black females. In addition, the 1981 Report of the
      Working Group on Arteriosclerosis of the NHLBI stated that research is needed to characterize
      the behaviors that create and maintain caloric imbalance. The initiative was approved by the
      September 1984 National Heart, Lung, and Blood Advisory Council and the Request for Proposals
      was released in November 1984.

      The NGHS I was initiated in 1985 as a contract-supported program with three field centers and
      a coordinating center. Annual exams were conducted at baseline and through the years of
      follow-up. The study was renewed by means of the cooperative agreement mechanism in 1992 as
      the NGHS II to permit two additional years of follow-up exams. The study was again renewed in
      1994 as NGHS III to continue annual examinations.

      DESIGN NARRATIVE:

      In this longitudinal study, there were a baseline examination and annual examinations. Data
      collected included: physical examination; anthropometric measurements; dietary information
      including food pattern and nutrient intake; physical activity; lipid, lipoprotein, and
      apolipoprotein profiles; family socioeconomic status; and psychosocial information. The study
      was renewed twice to continue the longitudinal investigation until the subjects reached the
      age of 19 to 20. Following the girls until that age allowed the documentation of the
      transition in risk factors when Black girls no longer have a cardiovascular risk advantage
      and to study the factors surrounding the transition. The longer follow-up also allowed for
      studies on the influence of smoking on body weight and the relationship of adolescent
      pregnancy to subsequent adiposity development, body fat patterning, blood pressure, and blood
      lipids.