Appendix 1—table 7. Mean thoracic vertebral BMD (mg/cm3) for Tsimane and Americansa by age category and sex.
| Age category (years) | Women | Men | Total | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Tsimane (N) | USc(N) | % difference (from US baseline)d | Tsimane (N) | USc
(N) |
% difference (from US baseline)d | Tsimane (N) | USc
(N) |
% difference (from US baseline)d | |
| 40–49 | 192.89 (80) | 204.33 (492) | −5.60 (p=0.004) |
192.33 (77) | 194.32 (895) | −1.02 (p=0.547) |
192.62 (157) | 197.87 (1387) | −2.65 (p=0.040) |
| 50–59 | 160.43 (89) | 177.79 (1164) | −9.76 (p<0.001) |
180.06 (98) | 173.13 (1708) | 4.00 (p=0.027) |
170.72 (187) | 175.02 (2872) | −2.46 (p=0.076) |
| 60–69 | 132.79 (49) | 153.90 (1204) | −13.72 (p=0.001) |
150.26 (56) | 158.46 (1422) | −5.18 (p=0.069) |
142.11 (105) | 156.37 (2626) | −9.12 (p<0.001) |
| ≥70b | 103.29 (27) | 127.14 (1048) | −18.76 (p<0.001) |
135.82 (31) | 139.27 (1097) | −2.48 (p=0.543) |
120.68 (58) | 133.34 (2145) | −9.50 (p=0.005) |
| Totale | 163.85 (245) | 179.91 (3908) | −8.93 (-----) |
176.21 (262) | 176.64 (5122) | −0.24 (-----) |
170.37 (507) | 177.61 (9030) | −4.08 (-----) |
aUS data represent asymptomatic subjects from greater Los Angeles (described in Budoff et al., 2010). Briefly, 9585 subjects (43% female; mean age = 56) underwent coronary artery calcification (CAC) scanning for evaluation of subclinical atherosclerosis, after exclusion of participants with vertebral deformities or fractures. Subjects had no known bone disease.
bMaximum age for Tsimane women and men = 91 and 94 years, respectively (US maximum age = 90 for both sexes).
cUS means are weighted by sample sizes (shown in Table 1 of Budoff et al., 2010). This table reports age sub-groups in two-year intervals (e.g. 41–42, 43–44, etc.); for two-year intervals spanning multiple decades that overlap with the age categories shown in this table (i.e. 39–40, 49–50, 59–60 and 69–70), we assume that each year of the two-year interval contributes 50% of the sample.
dP-value from a one-sample t test, including as the test value the weighted mean from Budoff et al. (2010).
eAge-standardized means are shown to account for differences in age distributions across populations. We use the Tsimane adult age distribution (calculated from the 2015 THLHP census) as the standard. To calculate age-standardized means, means for each age category and population (i.e. unadjusted means for Tsimane and weighted means for US) are multiplied by the proportional representation of that age category in the 2015 THLHP census, and then summed across all age categories.