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Type 2 Diabetes and Obesity in Mexican Pimas: Gene-Environment Interaction

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) )
ClinicalTrials.gov Identifier:
NCT01168297
First received: July 22, 2010
Last updated: November 11, 2014
Last verified: August 2014
  Purpose

In 1995 we conducted a cross-sectional study to identify the effects of traditional and western environments on prevalence of type 2 diabetes mellitus (T2DM) and obesity in Pima Indians in Mexico and the United States. The Mexican Pimas live in a remote mountainous region and at that time had experienced little change from their traditional lifestyle. Nothing was known about their T2DM prevalence. A similar number of non-Pima Mexicans live in the same village. In contrast to the Mexican Pimas, the U.S. Pimas live in more westernized society and have a high prevalence of diabetes. We found that although T2DM and obesity were more prevalent in Mexican Pimas than non-Pimas, both Mexican groups had a significantly lower prevalence of these disorders than U.S. Pimas. The lifestyle of the Mexican population studied included a dramatically higher level of physical activity and a diet higher in fiber and lower in calories derived from fat compared with the U.S. Pimas. Since the U.S. and Mexican Pimas share a similar gene pool we concluded that even in populations genetically prone to T2DM and obesity, their development is determined largely by environmental circumstances.

Since 1995 the environmental circumstances of the Mexican Pimas and non-Pimas have changed. The electrical supply to the region has increased, cars have become more prevalent and grocery stores have appeared. The impact of these changes on T2DM and obesity has not been examined. In light of these events, we propose to: 1) compare the current prevalence of T2DM and obesity in Mexican Pimas and non-Pima Mexicans to that present in 1995 with the same measures used previously, including height, weight, waist circumference, body composition by bioelectrical impedance, oral glucose tolerance and HbA1c; 2) compare current diet, physical activity and total energy expenditure in both Mexican Pimas and. non-Pima Mexicans using the same methods as the 1995 study to the previous results and 3) document the frequencies of T2DM and obesity-associated genetic variants in Mexican Pimas compared with U.S. Pimas and non-Pima Mexicans.


Condition
Type 2 Diabetes Mellitus
Obesity

Study Type: Observational
Study Design: Time Perspective: Prospective
Official Title: Type 2 Diabetes and Obesity in Mexican Pimas: Gene-Environment Interaction

Resource links provided by NLM:


Further study details as provided by National Institutes of Health Clinical Center (CC):

Primary Outcome Measures:
  • Diabetes

Estimated Enrollment: 900
Study Start Date: July 2010
Detailed Description:

In 1995 we conducted a cross-sectional study to identify the effects of traditional and western environments on prevalence of type 2 diabetes mellitus (T2DM) and obesity in Pima Indians in Mexico and the United States. The Mexican Pimas live in a remote mountainous region and at that time had experienced little change from their traditional lifestyle. Nothing was known about their T2DM prevalence. A similar number of non-Pima Mexicans live in the same village. In contrast to the Mexican Pimas, the U.S. Pimas live in more westernized society and have a high prevalence of diabetes. We found that although T2DM and obesity were more prevalent in Mexican Pimas than non-Pimas, both Mexican groups had a significantly lower prevalence of these disorders than U.S. Pimas. The lifestyle of the Mexican population studied included a dramatically higher level of physical activity and a diet higher in fiber and lower in calories derived from fat compared with the U.S. Pimas. Since the U.S. and Mexican Pimas share a similar gene pool we concluded that even in populations genetically prone to T2DM and obesity, their development is determined largely by environmental circumstances.

Since 1995 the environmental circumstances of the Mexican Pimas and non-Pimas have changed. The electrical supply to the region has increased, cars have become more prevalent and grocery stores have appeared. The impact of these changes on T2DM and obesity has not been examined. In light of these events, we propose to: 1) compare the current prevalence of T2DM and obesity in Mexican Pimas and non-Pima Mexicans to that present in 1995 with the same measures used previously, including height, weight, waist circumference, body composition by bioelectrical impedance, oral glucose tolerance and HbA1c; 2) compare current diet, physical activity and total energy expenditure in both Mexican Pimas and. non-Pima Mexicans using the same methods as the 1995 study to the previous results and 3) document the frequencies of T2DM and obesity-associated genetic variants in Mexican Pimas compared with U.S. Pimas and non-Pima Mexicans.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria
  • INCLUSION AND EXCLUSION CRITERIA:

Selection of Subjects:

-The entire adult population of Maycoba, Sonora, Mexico, will be invited to participate in the main study. Individuals will be eligible to participate if they are at least 18 years old and residents of Maycoba and able to give informed consent. There will be no further exclusion or inclusion criteria. For the doubly-labeled water studies pregnant women will be excluded, since pregnancy has profound effects on energy expenditure.

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01168297

Locations
Mexico
Centro de Investigacion en Alimentacion y Desarollo (CIAD)
Hermosillo, Mexico
Sponsors and Collaborators
Investigators
Principal Investigator: Robert L Hanson, M.D. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
  More Information

No publications provided

Responsible Party: National Institutes of Health Clinical Center (CC) ( National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) )
ClinicalTrials.gov Identifier: NCT01168297     History of Changes
Other Study ID Numbers: 999910161, 10-DK-N161
Study First Received: July 22, 2010
Last Updated: November 11, 2014
Health Authority: United States: Federal Government

Keywords provided by National Institutes of Health Clinical Center (CC):
Obesity
Type 2 Diabetes Mellitus
Genetics
Energy Expenditure
Physical Activity

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 2
Obesity
Body Weight
Endocrine System Diseases
Glucose Metabolism Disorders
Metabolic Diseases
Nutrition Disorders
Overnutrition
Overweight
Signs and Symptoms

ClinicalTrials.gov processed this record on November 25, 2014