Osteopenia and Osteoporosis Assessed by Dual X Absorptiometry in Sickle Cell Anemia Adults Subjects

Abstract

Background: Sickle cell anemia is the most common genetic disease in sub-Saharan Africa. It is an inherited autosomal recessive disorder characterized by chronic hemolysis secondary to falciformation of red blood cells, also responsible of ischemia, bone infarction and accompanied by serious infections and organic lesions.

Normal for weight at birth, Sickle cell anemia subjects have low pre puberty growth compared to normal children and also have compromised bone remodeling balance which results in decrease of bone mass and increase of bone fragility. Several studies have established that 37% to 50% of SCA patients were osteopenic or osteoporotic. This study aims to confirm the existence of bone remodeling disorders with osteoporotic translation and to compare the values found in Congolese sickle cell adults subjects to the general population.

Methods: Spine and hip DXA were conducted on 270 SS homozygotes aged 18 to 50 years (121 men and 149 women) and 359 AA homozygotes as controls (138 men and 221 women), aged from 18 to 50 years old, who agreed to participate in the study, considered as a control group. AS heterozygotes were not included in the study.

Results: AA subjects shows higher density (BMD) and Bone mineral content (BMC) values. Both SCA and AA controls showed the characteristic curve with peak bone mass at the fourth decade of life, followed by a decay with age. The difference in BMD and BMC with the control population ranged from 7.94% to 26.34% (average of 16.02%) which means -0.8 to -2.7 standard deviations, whereas, compared to the T -score in the Congolese population, was 11.6% to 22.15% less (average of -17.5%) equivalent of -0.9 to -2 standard deviations.

The overall decrease in bone mass rate for -2.5 DS of the T-score was: -28.4% and 33.2% for -2 DS of T-score.

Conclusion: SCA subjects shows high rate of osteopenia and osteoporosis and are more likely at risk for fractures.