Genetic factors have been implicated in the pathogenesis of osteoporosis, which is a common disorder in primary biliary cirrhosis (PBC). Insulin-like growth factor I (IGF-I) gene microsatellite repeat polymorphism was found to be associated with osteoporosis in some studies and collagen type Iα1 (COLIA1) Sp1 "s" allele was associated with lower bone mineral density (BMD) in PBC. IGF-I treatment restored osteopenia and reduced fibrogenesis in experimental cirrhosis. We investigated IGF-I and COLIA1 gene polymorphisms and BMD in Hungarian PBC patients. Patients and methods: 70 female patients with PBC were enrolled (mean age: 57.6 yrs, range: 37-76 yrs, each AMA M2 positive, stage II-IV). 139 age-matched female subjects served as controls (mean age: 55.9 yrs, range: 43-72 yrs). COLIA1 and IGF-I microsatellite repeat polymorphisms were determined by PCR. Bone mineral density (BMD) was measured by dual energy x-ray absorptiometry (Lunar, Prodigy, WI, USA) in lumbar spine (LS) and femoral neck (FN). Results: The IGF-I polymorphism was not different between PBC patients (192/192 = 34.2%, 194/192 = 28.6%, other = 37.2%) and controls (192/192 = 38.2%, 194/192 = 30.9%, other = 30.9%). The genotype frequency of COLIA1 polymorphism was also not different between PBC patients (SS = 72.9%, Ss = 22.8% and ss = 4.3%) and controls (SS = 58.4%, Ss = 35.9% and ss = 5.7%), however the "s" allele was significantly less frequent in patients with PBC (p = 0.038). Osteoporosis was present in 22 patients (31.4%). The IGF-1 192/192 allele was associated with higher FN Z-score compared to other genotypes (p = 0.036). Conclusions: In contrast to previous studies the "s" allele was less frequent in patients with PBC, and its presence was not associated with lower bone mineral density. Since IGF-I polymorphism was associated to BMD, it may be hypothesized that IGF-I microsatellite repeat polymorphism together with other genetic and environmental factors may be involved in the complex regulation of BMD in PBC.
|Translated title of the contribution||Decreased bone mineral density, insulin-like growth factor I (IGF-I) gene microsatellite repeat and collagen type /α1 Sp1 polymorphism in primary biliary cirrhosis|
|Number of pages||6|
|Publication status||Published - Feb 1 2004|
ASJC Scopus subject areas