Genetic variation of fasting glucose and changes in glycemia in response to 2-year weight-loss diet intervention: the POUNDS LOST trial.
Weight-loss intervention through diet modification has been widely used to improve obesity-related hyperglycemia; however, little is known about whether genetic variation modifies the intervention effect. We examined the interaction between weight-loss diets and genetic variation of fasting glucose on changes in glycemic traits in a dietary intervention trial.



The Preventing Overweight Using Novel Dietary Strategies (POUNDS LOST) trial is a randomized, controlled 2-year weight-loss trial. We assessed overall genetic variation of fasting glucose by calculating a genetic risk score (GRS) based on 14 fasting glucose-associated single nucleotide polymorphisms, and examined the progression in fasting glucose and insulin levels, and insulin resistance and insulin sensitivity in 733 adults from this trial.



The GRS was associated with 6-month changes in fasting glucose (P<0.001), fasting insulin (P=0.042), homeostasis model assessment of insulin resistance (HOMA-IR, P=0.009) and insulin sensitivity (HOMA-S, P=0.043). We observed significant interaction between the GRS and dietary fat on 6-month changes in fasting glucose, HOMA-IR and HOMA-S after multivariable adjustment (P-interaction=0.007, 0.045 and 0.028, respectively). After further adjustment for weight loss, the interaction remained significant on change in fasting glucose (P=0.015). In the high-fat diet group, participants in the highest GRS tertile showed increased fasting glucose, whereas participants in the lowest tertile showed decreased fasting glucose (P-trend <0.001); in contrast, the genetic association was not significant in the low-fat diet group (P-trend=0.087).



Our data suggest that participants with a higher genetic risk may benefit more by eating a low-fat diet to improve glucose metabolism.
Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA.|Shanghai Clinical Center for Endocrine and Metabolic Diseases, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
T
T
Wang
Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
T
T
Huang
Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Y
Y
Zheng
Pennington Biomedical Research Center of the Louisiana State University System, Baton Rouge, LA, USA.
J
J
Rood
Pennington Biomedical Research Center of the Louisiana State University System, Baton Rouge, LA, USA.
G A
GA
Bray
Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
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FM
Sacks
Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA.|Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
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L
Qi
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000235:genetics* / Q000378:metabolism*; D004038:Diet, Reducing; D005215:Fasting / Q000378:metabolism*; D005260:Female; D014644:Genetic Variation; D006442:Glycated Hemoglobin / Q000378:metabolism; D038321:Glycemic Index; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000235:genetics / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000178:diet therapy* / Q000453:epidemiology; D020641:Polymorphism, Single Nucleotide; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D015431:Weight Loss / Q000502:physiology*
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; C517652:hemoglobin A1c protein, human