Table 3.
Risk of Bias in Cross-Sectional Studies Designed to Assess BMD in Transgender People
| Study | Calcium/Vitamin D Supplements | Calcium Intake | Serum Vitamin D | Smoking | Alcohol Abuse | Physical Activity | Adjustments for BMD | Exclusion Criteria |
|---|---|---|---|---|---|---|---|---|
| Transgender men | ||||||||
| Van Caenegem et al. 2012 [11] | 6% | — | — | 28%; 7–12 pack-y | No | 8.4 ± 1.8 (Baecke’s) | Body weight and height | Illnesses or medications known to affect body composition, hormone levels, or bone metabolism; current or previous use (>2 y) of glucocorticoids, oral contraception, (anti)androgens (except CSHT in FtM), calcium and vitamin D supplements (allowed for FtM, n = 3), insulin, antiepileptic drugs, calcitonin, bisphosphonates, hypogonadism, untreated hyperthyroidism, cystic fibrosis, malabsorption, eating disorders, disorders of collagen or bone metabolism, chronic renal failure, alcohol abuse, autoimmune rheumatoid disease |
| Control natal women | None | — | — | 12%; 3–6 pack-y | No | 8.3 ± 1.5 (Baecke’s) | — | |
| Dan Broulik et al. 2018 [18] | — | — | 19.95 ± 11 ng/mL | 25% | No | — | — | Use of medications known to affect BMD other than calcium, vitamin D, or multivitamins, smoking >10 cigarettes daily, alcohol abuse |
| Control natal women | — | — | 38.5 ± 11.8 ng/mL | 20% | No | — | — | |
| Transgender women | ||||||||
| Reutrakul et al. 1998 [19] 13.9 mo |
— | 0.7 ± 0.2 Glasses of milk per wk | — | 2.3 ± 1.6 pack-y | — | 1.2 ± 0.5 y of physical activity (>3 times per wk) | Body weight | None of the subjects had medical history or risk factors for osteoporosis such as hyperparathyroidism, thyroid disorders, or glucocorticoid usage. |
| 59.8 mo | — | 0.5 ± 0.1 Glasses of milk per wk | — | 4.0 ± 0.9 pack-y | — | 4.3 ± 1.1 y of physical activity (>3 times/wk) | Body weight | |
| Sosa et al. 2003 [17] | None | 773.9 ± 257.9 mg/d | — | 48% | 68% | 36% (active) | Body weight and height | Drugs that might affect bone density, hepatic or renal disorders, alcoholism, Paget disease, gonadectomy, hyperparathyroidism, osteoporotic fracture, HIV infection |
| Control natal men | None | 652.1 ± 265.6 mg/d | — | 40% | 72% | 48% (active) | Body weight and height | |
| Lapauw et al. 2008 [12]a | — | 528 (431–772) mg/d | 23 (14–33) ng/mL | 43.5% | 1.5 (0.8–12) units/wk | 2.91 ± 0.71 (Baecke’s) | A multivariate analysis explored the contributions of muscle strength, physical activity, age, smoking, and calcium intake. Muscle strength predicted cortical bone size. Current smoking was associated with lower BMD at the lumbar spine. Negative association between calcium intake and periosteal or endosteal circumference, and positive association between physical activity and cortical BMC and bone area.b | — |
| Control natal men | — | 544 (423–804) mg/d | 18 (13–25) ng/mL | 17.4% | 9.0 (3.0–16.5) units/wk | 2.68 ± 0.79 (Baecke’s) | — | — |
| Fighera et al. 2018 [13] | — | — | — | — | — | — | — | Other treatment protocol |
Abbreviation: FtM, female to male.
a
Interquartile range.
b
Data not shown.