[Heritability of serum leptin levels: a twin study].
OBJECTIVE
To study the contribution of genetic factors to the variance of serum leptin concentration in healthy, normotensive twins.


METHODS
A total of 57 pairs of twins were investigated: 28 female and 19 male pairs of monozygotic(MZ) twins, and 6 female and 4 male pairs of dizygotic(DZ) twins. The zygosity of twins was determined by comparing the concordance of the genotype of nine fluorescence-labeled microsatellite markers. The genetic analysis was performed using the variance-based method. Serum leptin levels were determined in duplicate by a radioimmunoassay Kit (Linco Research, Inc., St. Charles, Missouri) as previously described.


RESULTS
The test of genetic variance revealed a significantly larger within-pair variance of serum leptin in the DZ twins, in comparison with the MZ twins. The corresponding heritability for serum leptin was 8%. Adjusted for BMI, gender, and uric acid (UA), the heritability for serum leptin was 0.18%. Log leptin correlated significantly with blood pressure (SBp r=0.355  P<0.001; DBp r=0.339  P<0.001). Stepwise multiple linear regression analysis revealed that only BMI, gender and UA were linked independently to serum leptin levels(R(2)=0.788, P<0.001).


CONCLUSIONS
The above data indicate that environmental factors other than genetic factors are important determinants of leptinemia in normal subjects.
Wu
Meihua
M
Ruijin Hospital/Shanghai Institute of Hypertension, Shanghai Second Medical University, Shanghai, 200025 P. R. China. Berkely@eastday.com
He
Qingbo
Q
Zhu
Dingliang
D
He
Xing
X
Wang
Guliang
G
Gao
Pingjing
P
Zhou
Huaifa
H
Zhang
Weizhong
W
Zhao
Guangsheng
G
D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D005260:Female; D005838:Genotype; D006801:Humans; D020738:Leptin / Q000097:blood / Q000235:genetics*; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D008875:Middle Aged; D014429:Twins, Dizygotic / Q000235:genetics*; D014430:Twins, Monozygotic / Q000235:genetics*
D020738:Leptin