Peak Bone Mineral Density Levels in Normal Omanis, a Pilot Study

Aims: To determine normal peak bone mineral density (PBMD) values in a cohort of healthy Omanis.
Study Design: Cross-sectional study.
Place and Duration of the study: in the Departments of Nuclear Medicine and Medicine at Sultan Qaboos University Hospital in Oman between 2012 and 2013.
Methodology: Omani employees aged between 25 to 34 years at Sultan Qaboos University Hospital (SQUH) were randomly chosen and invited to participate. Fifty normal males and 50 females were studied. Their fully informed consent was obtained to establish PBMD values using dual energy X-ray absorptiometry (DXA). Blood was also taken to determine their serum calcium, phosphate, alkaline phosphatase and parathyroid hormone (PTH) levels as well as a complete blood count (CBC), serum sodium, potassium and creatinine levels. Statistical analysis was done based on Hologic Delphi Reference Values on a reference curve generation using z-scores and the fitting a polynomial curve of third order. This data was interpolated, sampled and tested to verify the initial results.
Results: Our results show that normal Omani PBMD values of L1-L4 in women were 0.94 0.11 and in men 0.99 0.12 g/cm2. These are significantly lower than those of a normal Caucasian population by 26.5% in women P-value (<.001) and by 23.8% in men P-value (<.001). Only three subjects had values on or slightly above the mean Caucasian level but sixteen had values on or below -2SD. The blood tests were within the normal range in all subjects.
Conclusion: Omani mean PBMD values obtained in this study are substantially lower than Caucasian values. To avoid the use of inappropriate anti-resorptive therapy we should consider revising our reference range. We recommend using normal Asian reference values as they are almost identical to those obtained in this study until a normal reference range is established for this country.