Table 4.

Tsimane T-score^a (mean and proportions osteopenic, osteoporotic) by age using Tsimane and American female young adult reference groups.

	Young adult reference group
	Tsimane				American
		Proportion of women				Proportion of women
Age category (n)	Mean T-score	T-score ≥ −1 Normalb	−1 < T-score < −2.5 Osteopenic	T-score ≤ −2.5 Osteoporotic	Mean T-score	T-score ≥ −1 Normal	−1 < T-score < −2.5 Osteopenic	T-score ≤ −2.5 Osteoporotic
20–29 (27)	−0.01	0.93	0.07	0	−0.84	0.56	0.44	0
30–39 (28)	−0.67	0.61	0.39	0	−1.27	0.29	0.71	0
40–49 (26)	−0.51	0.62	0.38	0	−1.17	0.35	0.65	0
50–59 (13)	−0.87	0.54	0.46	0	−1.40	0.31	0.69	0
60–69 (8)	−1.79	0.25	0.38	0.38d	−1.99	0.25	0.38	0.38d
70–79c (5)	−2.96	0	0.20	0.80	−2.74	0	0.20	0.80
Total (107)	−0.68	0.63	0.31	0.07d	−1.28	0.36	0.58	0.07d

^aSee Methods for T-score definition.

^bThe WHO defines osteopenia (low bone mass) as a T-score between −1.0 and −2.5, and osteoporosis as a T-score ≤ −2.5. T-scores ≥ −1 are classified as normal.

^cTsimane women aged 75–79 are not represented (max. age = 75)

^dTotal ≠ 1 due to rounding error.