肥胖与糖尿病和基因

肥胖与糖尿病和基因

张咸宁[email protected]

Tel ： 13105819271; 88208367

Office: A705, Research Building

2014/03

肥胖（ obesity ） : increased body mass associated with excess fat stores

• 一种由多种因素引起的慢性代谢性疾病，以体内脂肪细胞的体积和细胞数增加致体脂占体重的百分比异常增高并在某些局部过多沉积脂肪为特点。

• 单纯性肥胖患者全身脂肪分布比较均匀，没有内分泌紊乱现象，也无代谢障碍性疾病，其家族往往有肥胖病史。

BMI = 体重 (kg) / 身高 (m)* 身高 (m)

• 体重指数 body mass index （ BMI ） < 18.5 kg·m-2 者为体重过低， 18.5 ～ 23.9 kg·m-2 为正常范围，≥ 24 kg·m-2 为超重；≥ 28 kg·m-2 为肥胖。

肥胖的遗传率： 20%~80%

• 遗传率（ heritability ， h2 ）：遗传因素在多基因遗传病发生因素中所占的比例。

•遗传率愈大，表明遗传因素对病因的贡献愈大。

疾病 遗传率精神分裂症 80%

哮喘 80%

唇裂 ±腭裂 76%

麻疹 16%

Heritability (Heritability (hh2): ): The proportion of the causation of a character that is due to genetic causes. CMZ -- CDZ

• h2 = -----------------------

100 -- CDZ

• • If If ccMZ MZ >> >> ccDZDZ then then hh2 is high (approaches 1) is high (approaches 1)

• • If If ccMZMZ = = ccDZ DZ then then hh2 is low (approaches 0) is low (approaches 0)

c = concordancec = concordance 发病一致性发病一致性 MZ = MZ = 同卵双生子同卵双生子 DZ = DZ = 异卵双生子异卵双生子

• Gene–environment interactions: There are a number of examples of environmental factors influencing genotype expression. These include impact of diet and physical activity on certain gene effects such as those influenced by adrenergic receptor ( 肾上腺素能受体 ) and UCP genotypes.

• Specific loci implicated by GWAS include FTO, PPARG, UCP and adrenergic receptor genes.