3.1Description of the study population
The flow chart of population screening was shown in Fig. 1. Totally, 3,815 patients aged ≥ 40 years old were screened. Among them, 591 patients missing the VCFs measurement, 251 patients missing complete dietary information, 31 patients with extreme energy intake, 173 patients missing femoral neck BMD measurement, 5 patients missing survival data, and 34 patients missing important covariates were excluded. Finally, 2,730 eligible VCFs patients were included. The basic characteristics and covariates of the population, stratified by survival and all-cause mortality, were presented in Table 1. Among 2,730 patients, 218 (7.99%) were all-cause death and 71 (2.60%) were CVD-cause death. The proportion of VCFs patients with higher aMED scores in the all-cause mortality group was lower than in the survival group (46.47% vs. 53.36%). Difference was found in age, race, the level of PIR, physical activity and femoral neck BMD, smoking, the history of hypertension, diabetes, CVD, CKD, anti-osteoporosis therapy and VCFs between two groups (all P < 0.05).
3.2Relationship between aMED score and all-cause and CVD-cause mortality in VCFs patients
We employed two weighted COX proportional hazard models to explore the association between aMED score and the risk of all-cause and CVD-cause mortality in VCFs patients, as presented in Table 2 and Table 3. After adjusting for age, marital status, PIR, smoking status, physical activity, hypertension, CVD and CKD, patients with VCFs were associated with the high risk of all-cause mortality compared with participants without VCF (HR = 1.75, 95%CI: 1.13–2.73); no significant correlation was found between aMED score and all-cause mortality. After adjusted age, marital status, physical activity, CKD and CVD, patients with VCFs were associated with the high risk of CVD-cause mortality compared with participants without VCFs (HR = 2.35, 95%CI: 1.12–4.91); no significant correlation was found between aMED score and CVD-cause mortality.
3.3Joint effect of aMED and VCFs on all-cause and CVD-cause mortality
The joint effect of aMED and VCFs on all-cause and CVD-cause mortality was depicted in Table 4 and Table 5. After adjusting for age, marital status, PIR, smoking, physical activity, hypertension, CKD and CVD in model 2, we observed patients with VCFs and low aMED score (< 6) were associated with highest risk of all-cause mortality (HR = 2.27, 95%CI: 1.25–4.13) compared with participants without VCFs and high aMED score (≥ 6). After adjusted age, marital status, physical activity, CKD and CVD, the results showed that patients with VCFs and low aMED score were associated with the highest risk of mortality compared with participants without VCFs and high aMED score (HR = 4.25, 95%CI: 1.64–11.06).
3.4Moderating effect of aMED score on all-cause and CVD-cause mortality in VCFs patients
The moderating effects of aMED score on all-cause and CVD-cause mortality in VCFs patients were shown in Table 6 and Table 7. We observed in lower aMED score group (< 6), VCFs patients had a high risk of all-cause mortality (HR = 2.26, 95%CI: 1.22–4.17); while in higher aMED score group (≥ 6), the risk of all-cause mortality was reduced in VCFs patients (HR = 1.36, 95%CI: 0.71–2.61). Similar results were also observed in CVD-mortality. In lower aMED group, compared to participant without VCFs, VCFs patients had a high risk of CVD-cause mortality (HR = 3.31, 95%CI: 1.28–8.57); while in higher aMED score group, the risk of CVD-cause mortality was reduced (HR = 1.53, 95%CI: 0.46–5.12). Taken together, high aMED score has a moderating effect on all-cause and CVD-cause mortality in VCFs patients.
3.5Joint effect of aMED score on all-cause and CVD-mortality in VCFs patients based on complications
Table 8 shows the joint effect of aMED score and all-cause mortality in VCFs patients based on the history of dyslipidemia, CVD and CKD. After adjustment for age, marital status, PIR, smoking, physical activity, hypertension, CKD and CVD, compared to the participants without VCFs and high aMED score, those with VCFs and low aMED score had a high risk of all-cause mortality, especially among patients with the history of dyslipidemia, CVD and CKD.
3.6 Moderating effect of aMED score on all-cause mortality in VCFs patients based on complications
Table 9 reports the moderating effect of aMED score on all-cause mortality in VCFs patients stratified by the history of dyslipidemia, CVD and CKD. After adjusted age, marital status, PIR, smoking, physical activity, hypertension, CKD and CVD, the moderating effect of aMED score on all-cause mortality among VCFs patients was still robust in patients with the history of dyslipidemia, CVD and CKD.
Table 1
Characteristics of VCFs patients
Variables | Total (N = 2730) | Survival (N = 2512) | All-cause death (N = 218) | Statistics | P |
Age, years, n (%) | | | | χ² = 53.573 | < 0.001 |
< 60 | 1490(60.28) | 1445(62.49) | 45(29.54) | | |
≥ 60 | 1240(39.72) | 1067(37.51) | 173(70.46) | | |
Gender, n (%) | | | | χ² = 0.003 | 0.955 |
Female | 1377(50.48) | 1279(50.46) | 98(50.71) | | |
Male | 1353(49.52) | 1233(49.54) | 120(49.29) | | |
Race, n (%) | | | | χ² = 6.576 | 0.005 |
Black | 535(10.01) | 489(9.93) | 46(11.26) | | |
White | 1234(70.91) | 1096(70.26) | 138(79.91) | | |
Others | 961(19.08) | 927(19.81) | 34(8.83) | | |
Educational level, n (%) | | | | χ² = 0.035 | 0.854 |
Less than high school | 601(15.27) | 570(15.23) | 31(16.06) | | |
High school or above | 2129(84.73) | 2011(84.77) | 118(83.94) | | |
Marital status, n (%) | | | | χ² = 0.851 | 0.371 |
No | 601(15.27) | 546(15.06) | 55(18.24) | | |
Yes | 2129(84.73) | 1966(84.94) | 163(81.76) | | |
PIR, n (%) | | | | χ² = 28.244 | < 0.001 |
<1 | 1650(65.53) | 1564(67.18) | 86(42.58) | | |
≥1 | 1080(34.47) | 948(32.82) | 132(57.42) | | |
Insurance, n (%) | | | | χ² = 0.240 | 0.632 |
No | 445(13.09) | 424(13.23) | 21(11.09) | | |
Yes | 2285(86.91) | 2088(86.77) | 197(88.91) | | |
Smoking, n (%) | | | | χ² = 15.304 | 0.001 |
No | 1478(54.59) | 1391(55.81) | 87(37.65) | | |
Yes | 1252(45.41) | 1121(44.19) | 131(62.35) | | |
Drinking, n (%) | | | | χ² = 4.215 | 0.058 |
No | 754(20.89) | 687(20.46) | 67(26.85) | | |
Yes | 1976(79.11) | 1825(79.54) | 151(73.15) | | |
Physical activity, MET·min/week, n (%) | | | | χ² = 45.098 | < 0.001 |
<450 | 1032(36.16) | 908(34.67) | 124(56.94) | | |
≥450 | 1698(63.84) | 1604(65.33) | 94(43.06) | | |
Sedentary time, hours, n (%) | | | | χ² = 2.161 | 0.162 |
<7.5 | 1400(49.05) | 1308(49.53) | 92(42.44) | | |
≥7.5 | 1330(50.95) | 1204(50.47) | 126(57.56) | | |
Menopausal status, n (%) | | | | χ² = 1.567 | 0.229 |
No | 793(29.29) | 741(29.69) | 52(23.78) | | |
Yes | 584(21.18) | 538(20.77) | 46(26.93) | | |
Inapplicable (male) | 1353(49.53) | 1233(49.54) | 120(49.29) | | |
Hypertension, n (%) | | | | χ² = 38.217 | < 0.001 |
No | 892(35.24) | 871(36.91) | 21(12.02) | | |
Yes | 1838(64.76) | 1641(63.09) | 197(87.98) | | |
Diabetes, n (%) | | | | χ² = 17.290 | 0.001 |
No | 2099(81.89) | 1955(82.78) | 144(69.53) | | |
Yes | 631(18.11) | 557(17.22) | 74(30.47) | | |
Dyslipidemia, n (%) | | | | χ² = 1.291 | 0.274 |
No | 599(22.01) | 557(22.37) | 42(16.99) | | |
Yes | 2131(77.99) | 1955(77.63) | 176(83.01) | | |
CVD, n (%) | | | | χ² = 42.471 | < 0.001 |
No | 2000(76.07) | 1897(77.67) | 103(53.75) | | |
Yes | 730(23.93) | 615(22.33) | 115(46.25) | | |
CKD, n (%) | | | | χ² = 80.939 | < 0.001 |
No | 2441(90.46) | 2297(91.88) | 144(70.64) | | |
Yes | 289(9.54) | 215(8.12) | 74(29.36) | | |
Nonsteroidal anti-inflammatory agents, n( %) | | | | χ² = 3.404 | 0.085 |
No | 2336(84.74) | 2164(85.35) | 172(76.28) | | |
Yes | 394(15.26) | 348(14.65) | 46(23.72) | | |
Anti-osteoporosis therapy, n (%) | | | | χ² = 9.705 | 0.007 |
No | 2679(98.46) | 2469(98.64) | 210(96.00) | | |
Yes | 51(1.54) | 43(1.36) | 8(4.00) | | |
Femoral neck BMD, gm/cm2, n (%) | | | | χ² = 8.844 | 0.009 |
Normal | 1420(50.18) | 1344(51.18) | 76(36.30) | | |
Osteopenia | 1310(49.82) | 1168(48.82) | 142(63.70) | | |
BMI, kg/m2, n (%) | | | | χ² = 1.042 | 0.362 |
<25 | 761(27.25) | 689(26.91) | 72(32.07) | | |
25–30 | 990(36.65) | 914(36.86) | 76(33.62) | | |
≥30 | 979(36.10) | 909(36.23) | 70(34.31) | | |
Total energy, kcal, Mean ± S.E | 2080.07 ± 23.88 | 2089.73 ± 28.08 | 1945.69 ± 80.12 | t = -1.494 | 0.157 |
aMED score, n (%) | | | | χ² = 1.760 | 0.204 |
<6 | 1220(47.10) | 1099(46.64) | 121(53.53) | | |
≥6 | 1510(52.90) | 1413(53.36) | 97(46.47) | | |
VCFs, n (%) | | | | χ² = 12.511 | 0.003 |
No | 2581(94.66) | 2392(95.18) | 189(87.40) | | |
Yes | 149(5.34) | 120(4.82) | 29(12.60) | | |
Time, Mean ± S.E | 71.08 ± 1.07 | 73.04 ± 1.12 | 43.79 ± 1.82 | t = -15.926 | < 0.001 |
Status, n (%) | | | | | |
Alive | 2512(93.29) | 2512(100.00) | 0(0.00) | | |
CVD-cause mortality | 71(1.97) | 0(0.00) | 71(29.40) | | |
Others-cause mortality | 147(4.74) | 0(0.00) | 147(70.60) | | |
S.E: Standard Error; t: Weighted t test; χ²: Rao-Scott Chi-square test; VCFs: vertebral compression fractures; PIR: poverty-to-income ratio; CVD: cardiovascular disease; CKD: chronic kidney disease; BMD: bone mineral density; BMI: body mass index; aMED: adherence to Mediterranean diet.
Table 2
Association between VCFs and aMED with all-cause mortality
| Model 1 | Model 2 |
Variables | HR (95%CI) | P | HR (95%CI) | P |
VCF | | | | |
No | Ref | | Ref | |
Yes | 2.65 (1.71–4.09) | < 0.001 | 1.75 (1.13–2.73) | 0.041 |
aMED score | | | | |
< 6 | Ref | | Ref | |
≥ 6 | 0.77 (0.58–1.03) | 0.200 | 0.95 (0.71–1.27) | 0.760 |
Ref: reference; VCFs: vertebral compression fractures; aMED: adherence to Mediterranean diet.
Model 1: crude model;
Model 2: adjustment for age, marital status, PIR, smoking, physical activity, hypertension, CKD and CVD.
Table 3
Association between VCFs and aMED with CVD-cause mortality
| Model 1 | Model 2 |
Variables | HR (95%CI) | P | HR (95%CI) | P |
VCF | | | | |
No | Ref | | Ref | |
Yes | 3.47 (1.67–7.21) | 0.004 | 2.35 (1.12–4.91) | 0.038 |
aMED score | | | | |
< 6 | Ref | | Ref | |
≥ 6 | 0.59 (0.34–1.01) | 0.082 | 0.74 (0.42–1.28) | 0.308 |
Ref: reference; HR: hazard ratio; CI: confidence interval; CVD: cardiovascular disease; VCFs: vertebral compression fractures; aMED: adherence to Mediterranean diet.
Model 1: crude model;
Model 2: adjustment for age, marital status, physical activity, CKD and CVD.
Table 4
Joint effect of aMED and VCFs to all-cause mortality
Variables | Model 1 | Model 2 |
HR (95%CI) | P | HR (95%CI) | P |
Joint | | | | |
Non-VCFs & aMED score ≥ 6 | Ref | | Ref | |
Non-VCFs & aMED score < 6 | 1.30 (0.95–1.77) | 0.247 | 1.02 (0.74–1.39) | 0.937 |
VCFs & aMED score ≥ 6 | 2.83 (1.48–5.42) | 0.003 | 1.39 (0.72–2.68) | 0.355 |
VCFs & aMED score < 6 | 3.18 (1.75–5.78) | 0.002 | 2.27 (1.25–4.13) | 0.025 |
Ref: reference; HR: hazard ratio; CI: confidence interval; VCFs: vertebral compression fractures; aMED: adherence to Mediterranean diet.
Model 1: crude model;
Model 2: adjustment for age, marital status, PIR, smoking, physical activity, hypertension, CKD and CVD.
Table 5
Joint effect of aMED and VCFs to CVD-cause mortality
Variables | Model 1 | Model 2 |
HR (95%CI) | P | HR (95%CI) | P |
Joint | | | | |
Non-VCFs & aMED score ≥ 6 | Ref | | Ref | |
Non-VCFs & aMED score < 6 | 1.67 (0.92–3.02) | 0.162 | 1.26 (0.69–2.29) | 0.515 |
VCFs & aMED score ≥ 6 | 3.38 (1.00-11.36) | 0.062 | 1.58 (0.47–5.39) | 0.479 |
VCFs & aMED score < 6 | 5.65 (2.18–14.64) | 0.005 | 4.25 (1.64–11.06) | 0.013 |
Ref: reference; HR: hazard ratio; CI: confidence interval; CVD: cardiovascular disease; VCFs: vertebral compression fractures; aMED: adherence to Mediterranean diet.
Model 1: crude model;
Model 2: adjustment for age, marital status, physical activity, CKD and CVD.
Table 6
The moderating effect of aMED score on all-cause mortality in VCFs patients
Variables | Model 1 | Model 2 |
HR (95%CI) | P | HR (95%CI) | P |
aMED score < 6 | | | | |
Non-VCFs | Ref | | Ref | |
VCFs | 2.45 (1.34–4.50) | 0.005 | 2.26 (1.22–4.17) | 0.002 |
aMED score ≥ 6 | | | | |
Non-VCFs | Ref | | Ref | |
VCFs | 2.85 (1.51–5.36) | 0.003 | 1.36 (0.71–2.61) | 0.371 |
Ref: reference; HR: hazard ratio; CI: confidence interval; VCFs: vertebral compression fractures; aMED: adherence to Mediterranean diet.
Model 1: crude model;
Model 2: adjustment for age, marital status, PIR, smoking, physical activity, hypertension, CKD and CVD.
Table 7
The moderating effect of aMED score on CVD-cause mortality in VCFs patients
| Model 1 | Model 2 |
Variables | HR (95%CI) | P | HR (95%CI) | P |
aMED score < 6 | | | | |
Non-VCFs | Refs | | Ref | |
VCFs | 3.36 (1.31–8.60) | 0.022 | 3.31 (1.28–8.57) | 0.018 |
aMED score ≥ 6 | | | | |
Non-VCFs | Ref | | Ref | |
VCFs | 3.36 (1.02–10.99) | 0.061 | 1.53 (0.46–5.12) | 0.490 |
Ref: reference; HR: hazard ratio; CI: confidence interval; CVD: cardiovascular disease; VCFs: vertebral compression fractures; aMED: adherence to Mediterranean diet.
Model 1: crude model;
Model 2: adjustment for age, marital status, physical activity, CKD and CVD.
Table 8
Joint effect of aMED and VCFs to all-cause mortality based on complications
Subgroup | Interaction | P |
Dyslipidemia | | |
No | Non-VCFs & aMED score ≥ 6 | Ref |
| Non-VCFs & aMED score < 6 | 0.765 |
| VCFs & aMED score ≥ 6 | 0.065 |
| VCFs & aMED score < 6 | 0.511 |
Yes | Non-VCFs & aMED score ≥ 6 | Ref |
| Non-VCFs & aMED score < 6 | 0.974 |
| VCFs & aMED score ≥ 6 | 0.765 |
| VCFs & aMED score < 6 | 0.040 |
CVD | | |
No | Non-VCFs & aMED score ≥ 6 | Ref |
| Non-VCFs & aMED score < 6 | 0.717 |
| VCFs & aMED score ≥ 6 | 0.363 |
| VCFs & aMED score < 6 | 0.376 |
Yes | Non-VCFs & aMED score ≥ 6 | Ref |
| Non-VCFs & aMED score < 6 | 0.818 |
| VCFs & aMED score ≥ 6 | 0.642 |
| VCFs & aMED score < 6 | < 0.001 |
CKD | | |
No | Non-VCFs & aMED score ≥ 6 | Ref |
| Non-VCFs & aMED score < 6 | 0.871 |
| VCFs & aMED score ≥ 6 | 0.390 |
| VCFs & aMED score < 6 | 0.554 |
Yes | Non-VCFs & aMED score ≥ 6 | Ref |
| Non-VCFs & aMED score < 6 | 0.965 |
| VCFs & aMED score ≥ 6 | 0.696 |
| VCFs & aMED score < 6 | 0.007 |
Ref: reference; VCFs: vertebral compression fractures; aMED: adherence to Mediterranean diet.
Table 9
The moderating effect of aMED score on all-cause mortality related to VCFs based on complications
Subgroup | aMED score (Outcome/Total) | HR (95%CI) | P |
Dyslipidemia | | | |
No | < 6 (n = 25/255) | 1.34 (0.22–8.17) | 0.765 |
| ≥ 6 (n = 17/344) | 2.57 (0.60-11.08) | 0.158 |
Yes | < 6 (n = 96/965) | 2.49 (1.29–4.80) | 0.009 |
| ≥ 6 (n = 80/1166) | 1.03 (0.48–2.22) | 0.945 |
CVD | | | |
No | < 6 (n = 57/873) | 1.55 (0.61–3.98) | 0.383 |
| ≥ 6 (n = 46/1127) | 1.36 (0.51–3.64) | 0.451 |
Yes | < 6 (n = 64/347) | 3.48 (1.56–7.74) | < 0.001 |
| ≥ 6 (n = 51/383) | 1.27 (0.54–2.96) | 0.684 |
CKD | | | |
No | < 6 (n = 78/1067) | 1.45 (0.60–3.50) | 0.476 |
| ≥ 6 (n = 66/1374) | 1.34 (0.61–2.92) | 0.451 |
Yes | < 6 (n = 43/153) | 3.64 (1.50–8.78) | < 0.001 |
| ≥ 6 (n = 31/136) | 1.26 (0.39–4.10) | 0.685 |
VCFs: vertebral compression fractures; aMED: adherence to Mediterranean diet.