Journal Club- Research Literature Review (Outline)
Health Effects of Childhood Obesity in Minority Children
Duni Cummings-John1, Jennifer Williams1
1
University of California, San Diego
School of Medicine
Post-Baccalaureate Program
Introduction
Research Topic:
The health disparity that we have chosen to further investigate is the disparate health
effects of childhood obesity on minority children.
Purpose:
Due to the rising epidemic of young minority children suffering from diseases such as
obesity, Type II diabetes as well as respiratory illnesses, we believe it is important to
examine the health status of today’s minority adolescents who are obese in comparison to
the entire population of obese adolescents.
Question:
Is there a higher incidence of chronic diseases among minority children who are obese?
Hypothesis:
The two hypotheses that we will test include:
Null (H0): There is no difference between the health consequences suffered by
minority children than those suffered by non-minority obese children.
Alternate (HA): A greater percentage of minority children who are obese are
more likely to develop weight-related diseases than non-minority children who
are obese as well as develop them earlier in life.
Background
The incidence of obesity has continued to rise drastically over the years,
particularly alarming in minority children and adolescents (Grier and Kumanyika, 2006).
Why would that be? Various studies have been done to not only look at some of the
suggested reasons as to why American children are gradually getting bigger but also why
minority children especially are suffering the most. Some explanations lie in behavioral
traits such as an immobile lifestyle (Marx, 2002). Other explanations, however, have
been proposed and tested that highlight the difference in socioeconomics as a major
concern to the rising epidemic of childhood obesity (Grier and Kumanyika, 2006; Pollack
and Strauss, 2001). We will explore the latter further.
This paper will focus on the diseases and health effects that disproportionately affect
minority children as a result of childhood obesity.
The articles and studies we found to be most supportive to our study included:
Addy, C. L., Heinze, H. J., Liese, A. D., Mayer-Davis, E. J., and Oeltmann, J. E.
(1999). Prevalence of Diagnosed Diabetes Among African-American and NonHispanic White Youth. Diabetes Care. 26, 2531-2535
In this study, the researchers conducted a test that documented diabetes
prevalence among African-American and non-Hispanic white youth in a two-county
region in South Carolina. They performed a population-based surveillance to identify
case subjects aged 0–18.9 years with a physician diagnosis of diabetes. They found that
diabetes prevalence was 1.7 cases per 1,000 youth and similar between African-American
and non-Hispanic white youth. Among older youth (10.0–18.9 years), non-Hispanic
white total prevalence was 2.5 per 1,000 and African-American prevalence was 3.1 per
1,000. They were able to conclude that Among African-American youth, the difference
in prevalence noted between younger and older age-groups was notably greater than that
observed among the non-Hispanic white youth, potentially reflecting a more marked
increase in diabetes incidence with age.
Wang, Y., and Zhang, Q. (2006). Are American children and adolescents of low
socioeconomic status at increased risk of obesity? Changes in the association
between overweight and family income between 1971 and 2002. American Journal
of Clinical Nutrition. 84(4), 707-716
The researchers of this particular study examined the secular trends in the
relations between overweight (body mass index in the 95th percentile) and
socioeconomic status (SES). They used nationally representative data collected from the
National Health and Nutrition Examination Surveys (NHANES) between 1971 and 2002
for 30,417 US children aged 2–18 years. The poverty income ratios used were low,
middle, and high SES. They were able to find considerable race, sex, and age differences
in the association between overweight and SES. Consistently across almost all SES
groups, the prevalence of overweight was much higher in blacks than in whites.
Dietz, W. H., Freedman, D. S., Khan, L. K., Ogden, C. L., and Serdula, M. K.
(2006). Racial and Ethnic Differences in Secular Trends for Childhood BMI,
Weight, and Height. Obesity. 14, 301-308.
Researchers examined differences in the secular trends for BMI, weight, and
height among white, black, and Mexican-American children. Their analyses used were
based on nationally representative data collected from 2 to 17 year olds in four
examinations (1971–1974 through 1999–2002). Overall, they found that black children
experienced much larger secular increases in BMI, weight, and height than did white
children. In most sex-age groups, Mexican-American children experienced increases in
BMI and overweight that were between those experienced by blacks and whites.
Marx, J. (2002) Unraveling the Causes of Diabetes. Science. 296(5568), 686-689.
In this study, the author highlights a study done on childhood diabetes. Sonia
Caprio of Yale School of Medicine is said to have found that a quarter of the 167 obese
children in the study showed the early stages of diabetes (impaired glucose tolerance).
25% were under the age of 10 and 21% were between 11-18 years old. 4% of the
adolescents were found to have full on diabetes. This study also suggests that some
ethnic groups may be more susceptible to diabetes than others. A study on uncovering
possible diabetes 2 susceptibility genes was conducted. Researchers uncovered a single
gene form of the disease (MODY). 2-3% of patients with diabetes also have MODY. It
was also found that a mutation in the MODY gene (HNF-1-a) causes a high rate of
diabetes type 2 in one particular indigenous population. Lastly, Garant and Shuldiner
report that mutations in the MODY gene contribute 25% of the diabetes 2 susceptibility
of African Americans.
Grier, S., and Kumanyika, S. (2006) Targeting Interventions for Ethnic Minority
and Low Income Populations. The Future of Children. 16(1), 187-207.
Researchers in this paper discuss differences in childhood obesity according to
race, ethnicity, and socioeconomic status. They conclude that differences in environment
increase the vulnerability of ethnic minorities to childhood obesity. Grier and
Kumanyika also site availability of wholesome foods in inner city neighborhoods as well
as safe places to exercise, as reasons for the disparate number of minority obese children.
Researchers used statistics from the National Center for Health Sciences to establish the
aforementioned point. Also, it is shown that minority obese children are experiencing the
health consequences of their weight at a disproportionately higher rate than white
counterparts (this includes Type 2 diabetes in blacks, and metabolic syndrome in
Mexicans). Most of the data here is from clinic records and case studies. “One study of
a sample of children (with an average age of 13.6 years) being evaluated for high blood
pressure found left ventricular hypertrophy in 70 percent of Hispanics, 39 percent of
African Americans, and 33 percent of whites. In an overnight sleep-monitoring
study of children aged two to eighteen years, African Americans had higher odds than
whites of having sleep apnea.”
Discussion
The methods used for conducting the literature review involved the PubMed
search engine and the JSTOR online archive. A variety of research studies that have been
done involving obese children (both minority and non-minority) were found to reference
in support of our own study.
In our completed research literature review, a summary of each study will be
prepared addressing the participants, research designs, results and conclusions drawn.
For outline purposes, we have simplified procedures to include a detailed description of
one study. Below is an example that would be similar to our own if we were to perform
the experiment ourselves.
Prevalence of Overweight and Obesity in Relation to Socio-economic
Conditions in Two Different Groups of School-age Children of Udaipur City
Two different types of schools were selected: (1) convent school (affluent group) and (2)
government school (non-affluent group). There were 268 children in affluent group and
250 in non- affluent group between ages of 12 to 17 years. The school fee of affluent
group was nearly Rs. 500 - 1,000 per month, while the school fees of non-affluent group
was much less. The exact age of the children was verified from the school records. A
semi-structured, pre-tested questionnaire was administered to each child to collect data on
socio- demographic profile (age, sex, and socio-economic status), dietary pattern, and
nutrient intake. Anthropometric measurements of weight, standing height, mid-arm
circumference (MUAC) and waist-hip ratio (WHR) were measured by utilizing standard
methodology13, 14. Weight was determined using weighing balance nearest to 100
grams; for height, erect scale was used up to an accuracy of 1 mm. The MUAC was
measured with the help of a non-stretchable tape. The international cut-off points for
body mass index were used for classifying children as overweight and obese. According
to this classification (i) if BMI analogue for age and sex is 25 kg/m2 and more, but less
than 30 kg/m2, then the child is overweight and; (ii) if BMI analogue for age and sex is
30 kg/m2 and more, then the child is obese.
Conclusion
It seems that the advent of childhood obesity, diabetes, heart disease, and other
weight related diseases have a higher incidence among children of ethnic backgrounds.
As noted in our literature review, childhood diabetes had an approximately 2 fold
increase among minority groups (African-American and Hispanic populations). In fact, it
was shown that low socioeconomic status in general is directly proportional to obesity.
In some studies, African-American children had a higher incidence of increase in BMI
over that of other ethnic youth. There are many factors that can be responsible for the
differences in the prevalence of weight related diseases. One school of thought suggests
that there are various environmental factors that cause ethnic youth to have a higher
incidence of obesity and thus weight related diseases. In fact, other sources, as
mentioned earlier in this paper, suggest that there exists a gene that causes a higher
susceptibility of diabetes among African- American populations. All in all, our literature
review seeks to explore the differences in the incidence of weight related diseases among
minority and non-minority children and their causes.
References
Addy, C. L., Heinze, H. J., Liese, A. D., Mayer-Davis, E. J., and Oeltmann, J. E. (1999).
Prevalence of Diagnosed Diabetes Among African-American and Non-Hispanic
White Youth. Diabetes Care. 26, 2531-2535
Dietz, W. H., Freedman, D. S., Khan, L. K., Ogden, C. L., and Serdula, M. K. (2006).
Racial and Ethnic Differences in Secular Trends for Childhood BMI, Weight, and
Height. Obesity. 14, 301-308.
Grier, S., and Kumanyika, S. (2006) Targeting Interventions for Ethnic Minority and
Low Income Populations. The Future of Children. 16(1), 187-207.
Kaneria, Y., Singh, P., and Sharma, D.C. (2006). Prevalence of Overweight and Obesity
in Relation to Socio-economic Conditions in Two Different Groups of School-age
Children of Udaipur City (Rajasthan). Journal, Indian Academy of Clinical
Medicine. 7(2): 133-5
Marx, J. (2002) Unraveling the Causes of Diabetes. Science. 296(5568), 686-689.
Wang, Y., and Zhang, Q. (2006). Are American children and adolescents of low
socioeconomic status at increased risk of obesity? Changes in the association
between overweight and family income between 1971 and 2002. American
Journal of Clinical Nutrition. 84(4), 707-716