OBJECTIVE: To examine the hypothesis of an association between a mtDNA D-loop Kpn I restriction site polymorphism (RSP) at base pair (bp) 16,133 (morph-1) and obesity in women. DESIGN: Comparisons of carriers and noncarriers of the mutation for BMI (Body Mass Index) levels and of the frequency of the mutation in obese and normal weight women. SUBJECTS: 567 unrelated adult Caucasian non-diabetic women from the HERITAGE Family Study (n = 63; BMI: 15-47 kg/m2), Quebec Family Study (QFS; 77 controls, BMI: 19-26 kg/m2 and 38 obese, BMI: 27-56 kg/m2) and Swedish Obese Subjects (SOS) Study (81 controls, BMI: 18-26 kg/m2 and 308 obese, BMI: 33-58 kg/m2). MEASUREMENTS: BMI was calculated from weight and height (kg/m2). mtDNA was amplified between base pair 15,928 and 16,500 by polymerase chain reaction (PCR) and digested with the restriction endonuclease Kpn I. RESULTS: No significant differences in the age-adjusted BMI for the mtDNA D-loop Kpn I RSP at base pair (bp) 16,133 (morph-1) between carriers and non-carriers in the HERITAGE cohort. No significant association was found between BMI and the Kpn I RSP carrier status in the SOS and QFS cohorts. The observed frequencies for the Kpn I RSP were not significantly (P > 0.05) different between the SOS controls and SOS obese irrespective of the degree of severity of obesity (BMI > 40, > 45 or > 50 kg/m2). CONCLUSION: We conclude that the mtDNA D-loop Kpn I RSP at bp 16,133 (morph-1) is not a determinant of human obesity.
Bibliographical noteFunding Information:
The authors acknowledge the financial support of the Medical Research Council of Canada (PG-11811, MT13960 and GR-15187) for the Québec Family Study and of Sweden (05239) for the Swedish Obese Subjects. The SOS project was also supported by the Swedish Ministry of Education, Hoffman-La Roche and Volvo Research Foundation. The HERITAGE Family Study is supported by the National Heart, Lung and Blood Institute of NIH through the following grants: HL47323, HL47317, HL47327, HL47321, and HL45670. Further, Jack H. Wilmore is partially supported by the Margie Gurley Seay Centennial Professorship, Art Leon is partially supported by the Henry L. Taylor Professorship in Exercise Science and Health Enhancement and Claude Bouchard is supported by the Donald B. Brown Research Chair on Obesity funded by the Medical Research Council of Canada and Roche Canada.
- Body mass index
- HERITAGE Family Study
- Quebec Family Study
- Swedish obese subjects