Abstract
Objectives: To assess ethnic differences in male reproductive hormone levels and to determine if any differences are explained by adiposity, insulin resistance (IR), or comorbidities in older men.
Design: Multi-ethnic cross-sectional observational study.
Participants: Community dwelling middle-aged and elderly men residing in the U.K. aged 40-84 years of South Asian (SA; n=180), White European (WE; n=328) or African Caribbean (AC; n=166) origin.
Observations: Measured testosterone (T), calculated free T (cFT), SHBG, and LH in SA, WE and AC men along with an assessment of body composition, IR, life-style factors and medical conditions.
Results: Age-adjusted mean T and cFT levels were lower in SA men when compared to WE and AC men (mean (SEM) T: SA: 14·0 ± 0·4; WE: 17·1 ± 0·3; AC: 17·2 ± 0·5 nmol/l, P < 0·001; cFT: SA: 283 ± 7; WE: 313 ± 5; AC: 314 ± 8 pmol/l, P < 0·006). Compared to WE and AC men, SA men had higher levels of body fat, IR, comorbidities and diabetes. After adjusting for body fat, IR and other confounders, T levels in SA men remained lower than in WE men (P = 0·04) but ethnic differences in cFT became nonsignificant. LH levels were higher in SA than WE men in age-adjusted and fully adjusted models.
Conclusions: T and cFT are lower in SA men than in WE and AC men. Whether ethnic-specific reference ranges for T and cFT might be appropriate in clinical practice requires further investigation. Ethnic differences in cFT, but not T, appear to be, more readily, explained by ethnic differences in adiposity, thus providing insights into potential pathophysiological mechanisms.
Design: Multi-ethnic cross-sectional observational study.
Participants: Community dwelling middle-aged and elderly men residing in the U.K. aged 40-84 years of South Asian (SA; n=180), White European (WE; n=328) or African Caribbean (AC; n=166) origin.
Observations: Measured testosterone (T), calculated free T (cFT), SHBG, and LH in SA, WE and AC men along with an assessment of body composition, IR, life-style factors and medical conditions.
Results: Age-adjusted mean T and cFT levels were lower in SA men when compared to WE and AC men (mean (SEM) T: SA: 14·0 ± 0·4; WE: 17·1 ± 0·3; AC: 17·2 ± 0·5 nmol/l, P < 0·001; cFT: SA: 283 ± 7; WE: 313 ± 5; AC: 314 ± 8 pmol/l, P < 0·006). Compared to WE and AC men, SA men had higher levels of body fat, IR, comorbidities and diabetes. After adjusting for body fat, IR and other confounders, T levels in SA men remained lower than in WE men (P = 0·04) but ethnic differences in cFT became nonsignificant. LH levels were higher in SA than WE men in age-adjusted and fully adjusted models.
Conclusions: T and cFT are lower in SA men than in WE and AC men. Whether ethnic-specific reference ranges for T and cFT might be appropriate in clinical practice requires further investigation. Ethnic differences in cFT, but not T, appear to be, more readily, explained by ethnic differences in adiposity, thus providing insights into potential pathophysiological mechanisms.
| Original language | English |
|---|---|
| Pages (from-to) | 660-668 |
| Number of pages | 9 |
| Journal | Clinical Endocrinology |
| Volume | 86 |
| Issue number | 5 |
| Early online date | 28 Feb 2017 |
| DOIs | |
| Publication status | Published - May 2017 |
Access to Document
- Marshall_2017_CE_EthnicDifferences_AAM
© 2017 Crown copyright. Clinical Endocrinology © 2017 John Wiley & Sons Ltd. This work has been made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at: https://doi.org/10.1111/cen.13305