Polymorphisms in the SCD1 gene: associations with body fat distribution and insulin sensitivity.
OBJECTIVE
Obesity and insulin resistance are major risk factors for metabolic diseases and are influenced by lifestyle and genetics. The lipogenic enzyme, stearoyl-coenzyme A-desaturase (SCD), is related to obesity. Further, SCD1-deficent mice are protected against obesity and insulin resistance. We hypothesized that genetic polymorphisms in the SCD1 gene would be associated with obesity, insulin sensitivity, and estimated SCD activity in humans.


METHODS
The study population was 1143 elderly Swedish men taking part of a population-based cohort study, the Uppsala Longitudinal Study of Adult Men. Associations between single nucleotide polymorphisms and obesity (waist circumference and BMI), insulin sensitivity (assessed by hyperinsulinemic euglycemic clamp), and estimated SCD activity (fatty acid ratios) were analyzed using linear regression analysis.


RESULTS
Subjects homozygous for the rare alleles of rs10883463, rs7849, rs2167444, and rs508384 had decreased BMI and waist circumference and improved insulin sensitivity. The rare allele of rs7849 demonstrated the strongest effect on both insulin sensitivity [regression coefficient (beta)=1.19, p=0.007] and waist circumference (beta=-4.4, p=0.028), corresponding to 23% higher insulin sensitivity and 4 cm less waist circumference.


CONCLUSIONS
This study indicates that genetic variations in the SCD1 gene are associated with body fat distribution and insulin sensitivity, results that accord well with animal data. These results need confirmation in other populations with a larger sample size.
Warensjö
Eva
E
Clinical Nutrition and Metabolism, Department of Public Health and Caring Sciences, Uppsala University, Uppsala Science Park, 751 85 Uppsala, Sweden. eva.warensjo@pubcare.uu.se
Ingelsson
Erik
E
Lundmark
Per
P
Lannfelt
Lars
L
Syvänen
Ann-Christine
AC
Vessby
Bengt
B
Risérus
Ulf
U
D000273:Adipose Tissue / Q000033:anatomy & histology*; D000368:Aged; D001794:Blood Pressure; D015992:Body Mass Index; D049628:Body Size; D015331:Cohort Studies; D004247:DNA / Q000097:blood / Q000235:genetics; D005091:Exons; D014644:Genetic Variation; D006801:Humans; D007438:Introns; D015810:Linkage Disequilibrium; D008137:Longitudinal Studies; D008297:Male; D020641:Polymorphism, Single Nucleotide; D013230:Stearoyl-CoA Desaturase / Q000235:genetics*; D013548:Sweden
D004247:DNA; C523776:SCD1 protein, human; D013230:Stearoyl-CoA Desaturase