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

NCT ID: NCT01168297

Last Updated: 2020-08-14

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 657 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2010-07-06
• Study Completion Date: 2020-08-07

Brief Summary

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.

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.

Conditions

Type 2 Diabetes Mellitus; Obesity

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: CROSS_SECTIONAL

Study Groups

Maycoba residents

Pima and non-Pima Mexicans from the village of Maycoba

No interventions assigned to this group

Eligibility Criteria

Exclusion Criteria

Selection of Subjects:

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 100 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

NIH

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Robert L Hanson, M.D.

Role: PRINCIPAL_INVESTIGATOR

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Locations

Centro de Investigacion en Alimentacion y Desarollo (CIAD)

Hermosillo, , Mexico

Countries

Mexico

Other Identifiers

10-DK-N161

Identifier Type: -

Identifier Source: secondary_id

999910161

Identifier Type: -

Identifier Source: org_study_id