Sir,
I refer to the interesting case–control study published by Agarwal et al.[1] in March–April 2020 issue of the International Journal of Trichology. On using ultrasound bone densitometer to estimate bone mineral density (BMD), the authors compared the grade of osteopenia in individuals with premature graying of hair (PGH) and those without PGH. They found that the mean BMD in the case group was 0.76 ± 1.00 compared to 0.68 ± 1.11 in the control group with no statistically significant difference (P = 0.649).[1] They concluded that was no significant correlation between PGH and steopenia.[1] I presume that due to the following methodological limitation, the study results ought to be cautiously interpreted. In the study methodology, the authors stated that BMD was assessed based on the World Health Organization (WHO) criteria in which T-score of BMD between 1.0 and 2.5 was regarded as osteopenia.[1] The impact of that limitation could be addressed in dual aspects.
First, it is noteworthy that WHO definition criteria of osteopenia using T-scores were introduced in 1994. Certain concerns have been raised on the correctness of the use of the WHO T-score thresholds for defining osteopenia which might be attributed to the inappropriateness of these definition criteria at skeletal sites other than the forearm, hip, and spine, or when other tools, such as quantitative ultrasound are utilized.[2]
Second, it is obvious that BMD normative data (BMDND) are controlled by different determinants, such as age, gender, weight, and race.[3] Based on these determinants, BMDND have been formulated for certain populations to be employed in the researches centers and clinical settings.[4,5] Since population in India has its unique characteristics, there is a need to construct national BMDND. Employing local standard is expected to yield a better idea on the association between steopenia and PGH.
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Conflicts of interest
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REFERENCES
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