|Year : 2019 | Volume
| Issue : 2 | Page : 114
Doppalapudi Nikhita1, P V. L. N Srinivasa Rao2, Suresh Vaikkakara3
1 Sri Padmavathi Medical College for Women, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India
2 Departments of Biochemistry, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India
3 Department of Endocrinology, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India
|Date of Web Publication||11-Nov-2019|
P V. L. N Srinivasa Rao
Senior Professor and Head, Department of Biochemistry, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Nikhita D, Srinivasa Rao P V, Vaikkakara S. Authors' response. J Clin Sci Res 2019;8:114
We read the comments on our paper by Mahmood Al-Mendalawi with interest. The authors have suggested the use of national reference values for elucidating the profile of disordered thyroid functions. We wish to clarify that in our study, serum thyroid-stimulating hormone (TSH) value level of 0.35-5.5 mIU/L was considered to be the normal range; and values >5.5 mIU/L were considered to be elevated. The age- and gender-specific reference ranges proposed by Marwaha et al. have been derived from Indian subjects and could thus be applicable. However, the authors did not find any significant difference in FT3 and TSH levels in between the genders in the respective age groups although the values were higher in women in the sixth decade compared to men. The 95th centile and 97th centile for TSH in normal healthy Indian women aged 18–35 years (the youngest age group mentioned) in the study by Marwaha et al. are 3.7 and 3.8 mIU/L, respectively. This value of TSH would be a rough approximation for application to the girls with the age group of 17–19 years that we studied. Applying the cutoff value of 3.7 mIU/L or above to our data, the number of women with hypothyroidism was 10 students in 70, thereby giving a prevalence of 14.3%. With the cutoff of 3.8 or above, the prevalence was the same (n = 10, 14.3%). This proportion is similar to the observations reported in another study from South India, which reported mild elevation in TSH levels (4.5–10 mIU/L) in 9.5% of young females. However, the reference ranges used clinically are 0.35–5.5 mIU/L. However, the reference ranges can be method-specific. The method used in the study by Marwaha et al., as well as in the study from South India, was electrochemiluminescence while we have used chemiluminescence method. A study comparing both the methods observed the analytical reference range for chemiluminescence (Architect) and electrochemiluminescence (Cobas) to be 0.35–4.9 mIU/L(μIU/mL) (n = 549) and 0.27–4.20 mIU/L (μIU/mL) (n = 516) in an Indian population. The reference range used in the present study thus matches with the method used, and thus, the results obtained in our study can be viewed as correct. We appreciate Al-Mendalawi for highlighting the importance of applying age- and gender-specific reference ranges.
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| References|| |
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