Calcitonin receptor gene polymorphisms at codon 447 in patients with osteoporosis and chronic periodontitis in South Indian population - An observational study.

CONTEXT: Chronic periodontitis and osteoporosis are multifactorial diseases which share common risk factors. Interactions between genetic and other factors determine the likely hood of osteoporotic fractures and chronic periodontitis. Calcitonin receptor (CTR) gene polymorphism is one of the important factors which contribute to the development of osteoporosis and chronic periodontitis.

AIMS: This study highlights the association of CTR gene polymorphisms at codon 447 in patients with osteoporosis and chronic periodontitis and healthy controls in south Indian population.

SETTINGS AND DESIGN: The study was designed as a case-control retrospective, observational clinical trial which was conducted to assess the role of CTR gene polymorphism in patients with osteoporosis and periodontitis as well as in healthy controls.

MATERIALS AND METHODS: A total of 50 subjects were taken into the study comprising of 20 healthy and 30 osteoporotic subjects with chronic periodontitis between the age group of 30-55 years. Within the limitations of our study, only 50 subjects were taken in the study due to the strict sampling method (Patients who were just diagnosed with osteoporosis and periodontitis and hence not taking any medication). 2 ml of blood sample was collected in ethylenediamine tetra acetic acid containing vials, and polymerase chain reaction was run to identify CTR gene polymorphism.

STATISTICAL ANALYSIS USED: Statistical analysis was done by student t -test. Pertaining to C > T allele pattern there was a significant difference between the test and control group.

RESULTS: A significant difference was observed between the test and control group in relation to the C > T allele pattern. Patients showing TT genotype distribution had greater periodontal destruction and lower bone-mineral density compared to CT genotype distribution followed by CC genotype distribution indicating TT homozygotes are more prone to the development of osteoporosis with increased risk of fracture and loss of alveolar bone. Males and females showed equal susceptibility to osteoporosis and chronic periodontitis.

CONCLUSIONS: CTR polymorphism at codon 447 may be associated with osteoporosis and chronic periodontitis.