Based on requirement of inclusion and exclusion criteria, we collected data from 3530 eligible participants in the 2011–2018 NHANES (Fig. 1). As the Table 1, Demographic characteristics of female participants are shown by the presence or absence of sarcopenia. Statistical results show that 330 participants ill with sarcopenia and 3200 participants without sarcopenia. Chi-square test showed marked disparity among multiple variables which are age (p < 0.001), race (p < 0.001), education (p < 0.001), marital status (p < 0.012), PIR (p < 0.002), marijuana or hashish use (p < 0.012), vigorous and moderate recreational activities (p < 0.001), parity (p < 0.016), BMXWAIST (p < 0.012), BMI (p < 0.012), ASM/BMI (p < 0.012). We found that participants with sarcopenia were more concentrated among those aged 41 to 60 years (70%), Mexican American (37.9%), and more than high school (44.5%), married (59.7%), less moderate recreational activity (87.6%), less vigorous recreational activity (64.8%), low income (42.7%). It is strange that marijuana or hashish was significantly associated with sarcopenia, but cocaine/heroin/meth- amphetamine was not.
Table 1
Demographic characteristics of female NHANES population a.
Characteristic | Total | Sarcopenia | Nonsarcopenia | P value |
No. (%) | No. (%) | No. (%) |
Total patients | 3530 | 330 (9.3) | 3200 (90.7) | |
Age, years | | | | < 0.001 |
20–40 | 1534 (43.5) | 99 (30.0) | 1436 (44.9) | |
41–60 | 1995 (56.5) | 231 (70.0) | 1764 (55.1) | |
Race | | | | < 0.001 |
Non-Hispanic white | 1266 (35.9) | 93 (28.2) | 1173 (36.7) | |
Non-Hispanic black | 808 (22.9) | 23 (7.0) | 785 (24.5) | |
Mexican American | 547 (15.5) | 125 (37.9) | 422 (13.2) | |
Other race | 909 (25.8) | 89 (27.0) | 820 (25.6) | |
Education | | | | < 0.001 |
Less than high school | 604 (17.1) | 97 (29.4) | 507 (15.8) | |
High school | 743 (21.0) | 86 (26.1) | 657 (20.5) | |
More than high school | 2183 (61.8) | 147 (44.5) | 2036 (63.6) | |
Marital status | | | | 0.012 |
Married | 1875 (53.1) | 197 (59.7) | 1678 (52.4) | |
Unmarried | 1655 (46.9) | 133 (40.3) | 1522 (47.6) | |
PIR | | | | 0.002 |
≤ 1.3 | 1240 (35.1) | 141 (42.7) | 1099 (34.3) | |
1.3–3.5 | 1255 (35.6) | 116 (35.2) | 1139 (35.6) | |
≥ 3.5 | 1035 (29.3) | 73 (22.1) | 962 (30.1) | |
Vigorous recreational activities | | | | < 0.001 |
Yes | 810 (22.9) | 41 (12.4) | 769 (24.0) | |
No | 2720 (77.1) | 289 (87.6) | 2431 (76.0) | |
Moderate recreational activities | | | | 0.001 |
Yes | 1547 (43.8) | 116 (35.2) | 1431 (44.7) | |
No | 1983 (56.2) | 214 (64.8) | 1769 (55.3) | |
Ever used marijuana or hashish | | | | < 0.001 |
Yes | 1709 (48.4) | 119 (36.1) | 1590 (49.7) | |
No | 1821 (51.6) | 211 (63.9) | 1610 (50.3) | |
Ever used cocaine/heroin/meth- amphetamine | | | | 0.818 |
Yes | 507 (14.4) | 46 (13.9) | 461 (14.4) | |
No | 3023 (85.6) | 284 (86.1) | 2739 (85.6) | |
Smoking status | | | | 0.108 |
Current | 762 (21.6) | 58 (17.6) | 704 (22.0) | |
Former | 540 (15.3) | 47 (14.2) | 493 (15.4) | |
Never | 2228 (63.1) | 225 (68.2) | 2003 (62.6) | |
Number of pregnancies | | | | 0.016 |
1–2 | 1451 (41.1) | 117 (35.5) | 1334 (41.7) | |
3–4 | 1410 (39.9) | 133 (40.3) | 1277 (39.9) | |
≥ 5 | 669 (19.0) | 80 (24.2) | 589 (18.4) | |
BMXWAIST (IQR) | 85.0, 108.0 | 95.4, 116.0 | 84.0, 106.7 | < 0.001 |
BMI (IQR) | 24.2, 34.2 | 29.8, 39.4 | 23.8, 33.5 | < 0.001 |
ASM/BMI (IQR) | 0.57, 0.70 | 0.46, 0.50 | 0.58, 0.71 | < 0.001 |
aFor categorical variables, P values were analyzed by chi-square tests. For continuous variables, the t-test for slope was used in generalized linear models.
PIR, Ratio of family income to poverty. BMXWAIST, waist circumference (cm). BMI, body mass index. ASM/BMI (IQR),appendicular skeletal muscle mass/ body mass index(interquartile range)
To further analyze the association between the parity and the incidence of sarcopenia, we also studied the population distribution characteristics according to the number of pregnancies (Table 2). As anticipated, participants with ≥ 5 parities among those variables have a higher proportion which aged 41–60 years, unmarried, PIR ≤ 1.3, without vigorous and moderate recreational activities, never smoked, ever used marijuana or hashish and never cocaine/heroin/meth-amphetamine. Among different races, participants with ≥ 5 parities are concentrated in non-Hispanic white and black, while the number of pregnancies increases with the level of education. Importantly, we found that the prevalence of sarcopenia increased with the parity, suggesting an association between sarcopenia and parity.
Table 2
Characteristics of the study population by number of pregnancies.
Characteristic | Number of pregnancies | P value |
1–2 | 3–4 | ≥ 5 |
Total patients | 1451 (41.1) | 1410 (39.9) | 669 (19.0) | |
Age, years | | | | < 0.001 |
20–40 | 748 (51.6) | 557 (39.5) | 230 (34.4) | |
41–60 | 703 (48.4) | 853 (60.5) | 439 (65.6) | |
Race | | | | < 0.001 |
Non-Hispanic white | 568 (39.1) | 505 (35.8) | 193 (28.8) | |
Non-Hispanic black | 308 (21.2) | 307 (21.8) | 193 (28.8) | |
Mexican American | 172 (11.9) | 245 (17.4) | 130 (19.4) | |
Other race | 403 (27.8) | 353 (25.0) | 153 (22.9) | |
Education | | | | < 0.001 |
Less than high school | 153 (10.5) | 276 (19.6) | 175 (26.2) | |
High school | 287 (19.8) | 310 (22.0) | 146 (21.8) | |
More than high school | 1011 (69.7) | 824 (58.4) | 348 (52.0) | |
Marital status | | | | 0.002 |
Married | 775 (53.4) | 783 (55.5) | 317 (47.4) | |
Unmarried | 676 (46.6) | 627 (44.5) | 352 (52.6) | |
PIR | | | | < 0.001 |
≤ 1.3 | 391 (26.9) | 508 (36.0) | 341 (51.0) | |
1.3–3.5 | 517 (35.6) | 517 (36.7) | 221 (33.0) | |
≥ 3.5 | 543 (37.4) | 385 (27.3) | 107 (16.0) | |
Vigorous recreational activities | | | | < 0.001 |
Yes | 373 (25.7) | 318 (22.6) | 119 (17.8) | |
No | 1078 (74.3) | 1092 (77.4) | 550 (82.2) | |
Moderate recreational activities | | | | < 0.001 |
Yes | 671 (46.2) | 634 (45.0) | 242 (36.2) | |
No | 780 (53.8) | 776 (55.0) | 427 (63.8) | |
Ever used marijuana or hashish | | | | 0.006 |
Yes | 724 (49.9) | 638 (45.2) | 347 (51.9) | |
No | 727 (50.1) | 772 (54.8) | 322 (48.1) | |
Ever used cocaine/heroin/meth- amphetamine | | | | < 0.001 |
Yes | 176 (12.1) | 195 (13.8) | 136 (20.3) | |
No | 1275 (87.9) | 1215 (86.2) | 533 (79.7) | |
Smoking status | | | | < 0.001 |
Current | 265 (18.3) | 311 (22.1) | 186 (27.8) | |
Former | 207 (14.3) | 234 (16.6) | 99 (14.8) | |
Never | 979 (67.5) | 865 (61.3) | 384 (57.4) | |
Sarcopenia | | | | 0.016 |
Yes | 117 (8.1) | 133 (9.4) | 80 (12.0) | |
No | 1334 (91.9) | 1277 (90.6) | 589 (88.0) | |
BMXWAIST (IQR) | 83.0, 106.7 | 85.7, 107.9 | 88.0, 110.8 | < 0.001 |
BMI (IQR) | 23.4, 33.6 | 24.3, 34.4 | 25.7, 35.0 | < 0.001 |
ASM/BMI (IQR) | 0.58, 0.71 | 0.56, 0.69 | 0.56, 0.69 | < 0.001 |
aFor categorical variables, P values were analyzed by chi-square tests. For continuous variables, the t-test for slope was used in generalized linear models.
PIR, Ratio of family income to poverty. BMXWAIST, waist circumference (cm). BMI, body mass index. ASM/BMI (IQR), appendicular skeletal muscle mass/ body mass index (interquartile range)
In order to ascertain the independent effect of the number of pregnancies on the risk of sarcopenia, we conducted subgroup analysis. We found that individuals with ≤ 2 pregnancies had a lower risk of sarcopenia (OR 0.90; 95% CI 0.76–1.06), while those with > 4 pregnancies had a higher risk of sarcopenia (OR 1.07; 95% CI 0.93–1.23). Subgroup analysis by age revealed that among individuals aged 20–40, those with ≤ 2 pregnancies had a decreased risk of sarcopenia (OR 0.97; 95% CI 0.70–1.36), while those with > 4 pregnancies had an increased risk (OR 1.01; 95% CI 0.79–1.30). Similar patterns were observed in the 41–60 age group, where ≤ 2 pregnancies were associated with a lower risk of sarcopenia, and > 4 pregnancies were associated with a higher risk. Furthermore, when analyzing different marital statuses, among married individuals, those with ≤ 2 pregnancies had a lower risk of sarcopenia (OR 0.90; 95% CI 0.76–1.06), while those with 4 pregnancies (OR 1.17; 95% CI 0.99–1.40), 6 pregnancies (OR 1.61; 95% CI 1.19–2.18), and 8 pregnancies (OR 2.22; 95% CI 1.26–3.94) had an increased risk. The risk of sarcopenia significantly increased with a higher number of pregnancies. Among unmarried individuals, the number of pregnancies did not appear to have an association with the risk of sarcopenia (Table 3).
The dose-response curve visually demonstrates that in different age groups, there is a direct positive relationship between the number of pregnancies and the risk or severity of sarcopenia when the number of pregnancies exceeds 4. In other words, as the number of pregnancies increases, the risk or severity of sarcopenia increases linearly, and this correlation is more pronounced in the 41–60 age group. Additionally, in the married population, there is a positive correlation between the number of pregnancies and sarcopenia, while no clear trend is observed in the unmarried population.
Table 3
Adjusted odds ratios for associations between the number of pregnancies and the presence of sarcopenia in NHANES 2011–2018 a.
Characteristic | Sarcopenia |
Number of pregnancies | 2 | 4 | 6 | 8 |
All | 0.90 (0.76–1.06) | 1.07 (0.93–1.23) | 1.18 (0.94–1.49) | 1.30 (0.85-2.00) |
20–40 years | 0.97 (0.70–1.36) | 1.01 (0.79–1.30) | 1.08 (0.69–1.68) | 1.16 (0.49–2.72) |
41–60 years | 0.92 (0.79–1.07) | 1.05 (0.85–1.28) | 1.17 (0.84–1.61) | 1.33 (0.82–2.16) |
Married | 0.86 (0.68–1.09) | 1.17 (0.99–1.40) | 1.61(1.19–2.18) | 2.22 (1.26–3.94) |
Unmarried | 0.94 (0.78–1.14) | 0.91 (0.70–1.20) | 0.82 (0.53–1.26) | 0.79 (0.40–1.54) |
aAdjusted covariates: Basic model: race, education levels, PIR, drug use, smoking status; Core model: basic model plus vigorous recreational activities, moderate recreational activities, BMXWAIST; Extended model: BMXBMI, ASM/BMI, Marital status, age. CI: confidence interval. aOR: adjusted odds ratio. T: tertile.
To eliminate or minimize the influence of unrelated confounding factors on the study results, we conducted propensity score matching (PSM) correction. The results showed that the population with ≤ 2 pregnancies (OR 0.96; 95%CI 0.82–1.13) was less likely to develop sarcopenia, while the population with > 4 pregnancies (OR 1.03; 95%CI 0.81–1.31) was more likely to develop sarcopenia. Subsequently, we further conducted stratified analysis. In the population aged 20–40, it was found that those with ≤ 2 pregnancies were less likely to develop sarcopenia (OR 0.85; 95%CI 0.67–1.08), while those with > 4 pregnancies (OR 1.16; 95%CI 0.83–1.64) were more likely to develop sarcopenia. Consistent with the above results, in the population aged 41–60, it was found that those with ≤ 2 pregnancies were less likely to develop sarcopenia, while those with > 4 pregnancies were more likely to develop sarcopenia. Subsequently, we analyzed different marital status groups. In the married population, it was found that those with ≤ 2 pregnancies (OR 0.86; 95%CI 0.69–1.09) were less likely to develop sarcopenia. However, as the number of pregnancies increased, the risk of sarcopenia significantly increased, as observed in those with 4 pregnancies (OR 1.11; 95%CI 0.93–1.32), 6 pregnancies (OR 1.27; 95%CI 0.96–1.70), and 8 pregnancies (OR 1.45; 95%CI 0.85–2.47). For the unmarried population, the risk correlation was not significant. (Table 4).
The dose-response curve after PSM correction still shows a certain risk correlation between the number of pregnancies and sarcopenia. Specifically, when the number of pregnancies exceeds 4, there is a positive relationship between the number of pregnancies and the risk or severity of sarcopenia in different age groups. In the married population, there is a positive correlation between the number of pregnancies and sarcopenia, while the risk correlation is lower in the unmarried population.
Table 4
Adjusted odds ratios for associations between the sarcopenia and number of pregnancies in NHANES 2011–2018 a.
Characteristic | Sarcopenia |
Number of pregnancies | 2 | 4 | 6 | 8 |
All | 0.96 (0.82–1.13) | 1.03 (0.81–1.31) | 1.07 (0.74–1.55) | 1.10 (0.61–1.96) |
20–40 years | 0.85 (0.67–1.08) | 1.16 (0.83–1.64) | 1.36 (0.80–2.31) | 1.45 (0.68–3.07) |
41–60 years | 0.91 (0.74–1.12) | 1.06 (0.90–1.23) | 1.16 (0.88–1.53) | 1.27 (0.76–2.14) |
Married | 0.86 (0.69–1.09) | 1.11 (0.93–1.32) | 1.27 (0.96–1.70) | 1.45 (0.85–2.47) |
Unmarried | 0.91 (0.76–1.10) | 1.06 (0.80–1.40) | 1.09 (0.70–1.69) | 1.07 (0.53–2.16) |
aAdjusted covariates: Basic model: race, education levels, PIR, drug use, smoking status; Core model: basic model plus vigorous recreational activities, moderate recreational activities, BMXWAIST; Extended model: BMXBMI, ASM/BMI, Marital status, age. CI: confidence interval. aOR: adjusted odds ratio. T: tertile.