The characteristics and anthropometric indices of the study participants stratified by sex are presented in Table 1. The mean ages of males and females were 64.15 ± 8.43 years and 62.72 ± 8.11 years, respectively. There were no significant differences in BMI between men and women (24.17 ± 5.62 vs. 25.02 ± 4.91 kg/m2, P = 0.583). Both WC and VAT area were significantly greater in men than in women (88.69 ± 9.85 vs. 84.92 ± 9.43 cm; 170.42 ± 68.78 vs. 140.27 ± 54.21 cm2, respectively, P < 0.001). Furthermore, SBP and DBP showed the same tendency in men as in women. Compared to women, men had greater VAT area (170.42 ± 68.78 vs. 140.27 ± 54.21 cm2, P < 0.001) but lower SAT area (104.87 ± 50.27 vs. 153.26 ± 64.61 cm2, P < 0.001). The adipose tissue area stratified by sex and BMI level is shown in Fig. 2. Visceral adipose tissue area was significantly greater in men than in women at every BMI level (P < 0.01). In contrast, women had greater subcutaneous adipose tissue area than men at every BMI level (P < 0.01).In both men and women, the conventional anthropometric indices, such as BMI, WC and HC, in the hypertension group were significantly greater than those in the group without hypertension. For the QCT–derived anthropometric indices, compared to women, men had a greater VAT area but lower SAT area in both the hypertension group and the group without hypertension in both males and females (P < 0.001, respectively).
Table 1
The anthropometric indicators of adiposity in both sexes by hypertensive status
| | Men | | | Women | |
| Total | Without hypertension (n = 207) | Hypertension (n = 307) | | Total | Without hypertension (n = 576) | Hypertension (n = 398) | P |
Age (year) | 64.15 ± 8.43 | 64.54 ± 8.05 | 63.88 ± 8.69 | | 62.72 ± 8.11 | 61.51 ± 8.01 | 64.71 ± 7.89 | 0.002 |
Height (cm) | 167.50 ± 6.78 | 167.17 ± 6.08 | 167.72 ± 7.22 | | 156.76 ± 5.75 | 157.01 ± 5.88 | 156.41 ± 5.56 | < 0.001 |
Weight (kg) | 71.50 ± 14.43 | 68.34 ± 14.01 | 73.64 ± 14.17* | | 64.01 ± 11.74 | 60.45 ± 12.70 | 64.28 ± 9.75& | < 0.001 |
BMI (kg/m2) | 24.17 ± 5.62 | 24.19 ± 5.29 | 25.84 ± 5.75* | | 25.02 ± 4.91 | 24.34 ± 5.07 | 26.00 ± 4.48& | 0.583 |
WC (cm) | 88.69 ± 9.85 | 84.89 ± 8.52 | 91.24 ± 9.86* | | 84.92 ± 9.43 | 82.59 ± 8.68 | 88.30 ± 9.47& | < 0.001 |
HC (cm) | 98.57 ± 9.18 | 96.17 ± 9.47 | 100.11 ± 8.66* | | 97.65 ± 8.25 | 95.98 ± 7.69 | 99.99 ± 8.44& | 0.060 |
VAT (cm2) | 170.42 ± 68.78 | 138.13 ± 56.06 | 192.19 ± 68.07* | | 140.27 ± 54.21 | 124.51 ± 48.13 | 163.08 ± 54.45& | < 0.001 |
SAT (cm2) | 104.87 ± 50.27 | 92.40 ± 47.52 | 113.27 ± 50.39* | | 153.26 ± 64.61 | 146.89 ± 62.49 | 162.47 ± 66.57& | < 0.001 |
SBP (mmHg) | 141.66 ± 18.51 | 124.57 ± 9.82 | 153.18 ± 13.36* | | 135.63 ± 20.02 | 122.94 ± 10.63 | 154.01 ± 15.71& | < 0.001 |
DBP (mmHg) | 80.45 ± 11.50 | 74.41 ± 7.63 | 84.51 ± 11.89* | | 78.40 ± 10.56 | 73.75 ± 7.76 | 85.13 ± 10.46& | 0.001 |
Values are means ± standard deviations. *p < 0.01 compared with the group without hypertension in men; &p < 0.01 compared with the group without hypertension in women |
BMI, body mass index; WC, waist circumference; HC, hip circumference; VAT, visceral adipose tissue; SAT, subcutaneous adipose tissue; SBP, systolic blood pressure; DBP, diastolic blood pressure. |
Correlations of VAT or SAT area with conventional anthropometric measures
Age-adjusted correlations of VAT and SAT area with conventional anthropometric measures stratified by sex are displayed in Table 2. The conventional anthropometric measures (BMI, WC, HC) were all significantly associated with VAT as well as SAT area (P < 0.001). Among the conventional adiposity measures, WC showed the best correlation not only with VAT area in men and women (r = 0.642 in men, r = 0.610 in women, P < 0.001, respectively) but also with SAT area in men and women (both P < 0.001).
Table 2
Age-adjusted Pearson correlation coefficients between simple anthropometric indices and VAT and SAT area
| Men | | Women |
VAT | P | | SAT | P | | VAT | P | | SAT | P |
BMI | 0.357 | < 0.001 | | 0.313 | < 0.001 | | 0.465 | < 0.001 | | 0.480 | < 0.001 |
WC | 0.642 | < 0.001 | | 0.505 | < 0.001 | | 0.610 | < 0.001 | | 0.561 | < 0.001 |
HC | 0.453 | < 0.001 | | 0.375 | < 0.001 | | 0.521 | < 0.001 | | 0.502 | < 0.001 |
BMI, body mass index; WC, waist circumference; HC, hip circumference; VAT, visceral adipose tissue; SAT, subcutaneous adipose tissue. |
Age-adjusted Correlations of anthropometric measures with SBP and DBP
Age-adjusted correlations of anthropometric measures with SBP and DBP are shown in Table 3. The conventional anthropometric indices, such as BMI, WC, and HC, as well as VAT and SAT area were all significantly correlated with DBP and SBP (P < 0.001). VAT area in men showed a higher correlation with SBP than that in women (r = 0.469 in men, r = 0.388 in women). Among the conventional anthropometric indices, WC also showed higher correlations with SBP in men than in women (r = 0.348 in men, r = 0.321 in women). In contrast, compared to women, SAT area showed lower correlations with DBP in men than in women (r = 0.104 in men, r = 0.164 in women).
Table 3
Pearson correlation coefficients between anthropometric indices and blood pressure level after adjustment for age
| Men | | Women |
SBP | P | | DBP | P | | SBP | P | | DBP | P |
BMI | 0.154 | < 0.001 | | 0.095 | 0.039 | | 0.222 | < 0.001 | | 0.186 | < 0.001 |
WC | 0.348 | < 0.001 | | 0.179 | < 0.001 | | 0.321 | < 0.001 | | 0.272 | < 0.001 |
HC | 0.238 | < 0.001 | | 0.112 | 0.021 | | 0.272 | < 0.001 | | 0.202 | < 0.001 |
VAT | 0.469 | < 0.001 | | 0.212 | < 0.001 | | 0.388 | < 0.001 | | 0.239 | < 0.001 |
SAT | 0.198 | < 0.001 | | 0.104 | 0.024 | | 0.151 | < 0.001 | | 0.164 | < 0.001 |
BMI, body mass index; WC, waist circumference; HC, hip circumference; VAT, visceral adipose tissue; SAT, subcutaneous adipose tissue; SBP, systolic blood pressure; DBP, diastolic blood pressure |
The correlations of anthropometric indices with SBP and DBP in the linear regression model
The results of the multiple linear regression analyses for the sex-specific associations of anthropometric measures and SBP and DBP are presented in Table 4. In men, a one standard deviation increment in VAT area was positively associated with SBP (β = 0.444,P < 0.001) as well as DBP (β = 0.146, P < 0.021) after controlling for age, body weight, height and BMI. In women, similar results were obtained, showing significant associations between VAT area and SBP (β = 0.309, P < 0.001) and DBP (β = 0.099, P = 0.034). Among conventional anthropometric measures, only WC in women was significantly associated with SBP (β = 0.148༌P = 0.007) and DBP (β = 0.198༌P = 0.001). In contrast to the above findings, there was an inverse association of SAT area with DBP (β= -0.105༌P = 0.009) in women, and SAT area had no significant correlation with SBP or DBP in men.
Table 4
The correlations of anthropometric indices with SBP and DBP levels from the multiple linear regression model
Adiposity indices | SBP | | DBP |
β | P | β | P |
Men | |
BMI | 0.004 | 0.989 | | 0.176 | 0.532 |
HC | -0.002 | 0.975 | | -0.023 | 0.737 |
WC | 0.140 | 0.081 | | 0.100 | 0.247 |
VAT | 0.444 | < 0.001 | | 0.146 | 0.021 |
SAT | -0.078 | 0.143 | | -0.020 | 0.724 |
Women | |
BMI | -0.120 | 0.753 | | 0.451 | 0.275 |
HC | 0.051 | 0.315 | | -0.053 | 0.335 |
WC | 0.148 | 0.007 | | 0.198 | 0.001 |
VAT | 0.309 | < 0.001 | | 0.099 | 0.034 |
SAT | -0.105 | 0.009 | | -0.019 | 0.663 |
BMI, body mass index; WC, waist circumference; HC, hip circumference; VAT, visceral adipose tissue; SAT, subcutaneous adipose tissue; SBP, systolic blood pressure; DBP, diastolic blood pressure |
Multivariable-adjusted regression model of hypertension and anthropometric indices
The results of the binary logistic regression analyses for the sex-specific association of hypertension with conventional anthropometric indices as well as abdominal adiposity measures are summarized in Table 5. Two models were generated in stages: the multivariable-adjusted models, with covariates including age, height, weight, HC, WC, and BMI; and a second model in which the first model was also adjusted for VAT and SAT area. We found that WC was significantly associated with an increased risk of hypertension in both men (OR = 1.089, P < 0.001) and women (OR = 1.063, P < 0.001). When additionally adjusted for VAT and SAT area, VAT area correlated with an increased risk of hypertension more in men than in women (OR = 1.013 in men, OR = 1.011 in women, P < 0.001, respectively). WC correlated with an increased risk of hypertension only in women (OR = 1.039, P = 0.002). However, there was a borderline but not significant association between WC and an increased risk of hypertension (OR = 1.040, P = 0.059) in men. SAT area and HC were not significantly associated with an increased risk of hypertension in either women or men in the model. The optional cutoff values and corresponding sensitivity, specificity and area under the curve (AUC) of each adiposity index for identifying the best predicted increased risk of hypertension are presented in Table 6 and Fig. 3. WC and VAT area yielded higher AUCs than BMI and HC in both women and men (P < 0.05). The Youden index indicated that the optimal WC cutoff value was 86.5 cm in men and 87.0 cm in women and that the optimal VAT area cutoff value was 173.77 cm2 in men and 138.91 cm2 in women. The Youden index for VAT area was highest among the measured anthropometric indices regardless of sex.
Table 5
Sex-specific multivariable-adjusted regressions for anthropometric indicators of adiposity with hypertension status
Indicators of adiposity | Hypertension |
Men | | Women |
OR | 95% CI | P | | OR | 95% CI | P |
Model 1 | | | | | | | |
WC | 1.089 | [1.049, 1.129] | < 0.001 | | 1.063 | [1.035, 1.093] | < 0.001 |
Model 1 + VAT and SAT | | | | | | | |
WC | 1.040 | [0.999,1.083] | 0.059 | | 1.039 | [1.018,1.078] | 0.002 |
VAT | 1.013 | [1.008,1.017] | < 0.001 | | 1.011 | [1.007,1.015] | < 0.001 |
SAT | 0.999 | [0.993,1.004] | 0.712 | | 0.998 | [0.995,1.001] | 0.291 |
BMI, body mass index; WC, waist circumference; HC, hip circumference; VAT, visceral adipose tissue; SAT, subcutaneous adipose tissue. |
Table 6
Comparison of ROC analyses of the association of hypertension and anthropometric indices of adiposity by sex
Variables | AUC (95% CI) | P | Cutoff | Sensitivity | Specificity | Youden Index |
Men | | | | | | |
BMI (kg/m2) | 0.654 [0.611,0.696] | < 0.001 | 24.69 | 0.64 | 0.62 | 0.26 |
HC (cm) | 0.658 [0.614,0.700] | < 0.001 | 100.6 | 0.49 | 0.78 | 0.27 |
WC (cm) | 0.706 [0.664,0.746] | < 0.001 | 86.5 | 0.70 | 0.61 | 0.31 |
VAT(cm2) | 0.732 [0.690,0.770] | < 0.001 | 173.77 | 0.58 | 0.76 | 0.34 |
Women | | | | | | |
BMI (kg/m2) | 0.651 [0.619,0.681] | < 0.001 | 25.25 | 0.59 | 0.66 | 0.24 |
HC(cm) | 0.638 [0.606,0.668] | < 0.001 | 97.5 | 0.57 | 0.64 | 0.21 |
WC (cm) | 0.674 [0.643,0.704] | < 0.001 | 87.0 | 0.49 | 0.75 | 0.25 |
VAT(cm2) | 0.703 [0.673,0.732] | < 0.001 | 138.91 | 0.64 | 0.67 | 0.31 |
BMI, body mass index; WC, waist circumference; HC, hip circumference; VAT, visceral adipose tissue; |