Baseline characteristics of participants
The average age of participants was 49.31±11.16 years old, and about 57.14% of them were male and 42.88% female. The baseline characteristics were listed in Table 1. Depending on the MHR, participants were divided into MHR low-level, medium-level, and high-level groups. There was no statistically significant difference in age and LDL-C among the different MHR groups. Compared with the MHR low-level group, ALT, AST, BMI, SBP, DBP, fasting glucose, and serum uric acid were significantly higher and TC was significantly lower in the medium-level and high-level groups.
Table 1
Baseline characteristics of participants
MHR | Low-level group | Middle-level group | High-level group | P-value |
Number | 214 | 216 | 216 | |
AGE (years, mean±SD) | 49.40 ± 11.11 | 49.81 ± 10.90 | 48.70 ± 11.47 | 0.579 |
LDL-C (mmol/L, mean±SD) | 2.72 ± 0.70 | 2.86 ± 0.71 | 2.80 ± 0.68 | 0.115 |
TC (mmol/L, mean±SD) | 4.92 ± 0.90 | 4.88 ± 0.90 | 4.71 ± 0.86 | 0.044 |
ALT (U/L, median, min-max) | 15.00 (4.00-67.00) | 19.00 (2.00-130.00) | 26.00 (5.00-112.00) | <0.001 |
AST (U/L, mean±SD) | 22.26 ± 6.55 | 23.63 ± 9.57 | 25.22 ± 8.77 | 0.001 |
BMI (kg/m2, mean±SD) | 22.19 ± 2.84 | 23.77 ± 3.14 | 25.60 ± 3.03 | <0.001 |
SBP (mmHg, mean±SD) | 119.64 ± 16.25 | 122.72 ± 15.51 | 127.55 ± 16.39 | <0.001 |
DBP (mmHg, mean±SD) | 71.01 ± 10.87 | 74.47 ± 10.67 | 78.00 ± 11.43 | <0.001 |
Fasting glucose (mmol/L, mean±SD) | 4.87 ± 0.58 | 5.09 ± 0.80 | 5.25 ± 1.22 | <0.001 |
Uric acid (umol/L, mean±SD) | 310.88 ± 72.25 | 360.71 ± 88.72 | 404.25 ± 94.84 | <0.001 |
SEX (n,%) | | | | <0.001 |
Male | 64 (29.91%) | 127 (58.80%) | 178 (82.41%) | |
Female | 150 (70.09%) | 89 (41.20%) | 38 (17.59%) | |
Smoking status (n,%) | | | | <0.001 |
Nonsmokers | 194 (90.65%) | 154 (71.63%) | 114 (52.78%) | |
Occasional smoking | 7 (3.27%) | 16 (7.44%) | 14 (6.48%) | |
Smokers | 13 (6.01%) | 45 (20.93%) | 88 (40.74%) | |
Drinking state (n,%) | | | | <0.001 |
Nondrinkers | 151 (70.56%) | 113 (525.6%) | 84 (38.89%) | |
Occasional drinking | 44 (20.56%) | 62 (28.84%) | 79 (36.57%) | |
Drinkers | 19 (8.88%) | 40 (18.60%) | 53 (24.54%) | |
Exercise status (n,%) | | | | 0.229 |
Low-intensity group | 171 (79.91%) | 172 (79.63%) | 157 (72.69%) | |
Medium-intensity group | 29 (13.55%) | 25 (11.57%) | 33 (15.28%) | |
High-intensity group | 14 (6.54%) | 19 (8.80%) | 26 (12.04%) | |
LDL-C low-density lipoprotein cholesterol, TC total cholesterol, ALT alanine aminotransferase, AST aspartate transaminase, BMI body mass index, SBP systolic blood pressure, DBP diastolic blood pressure |
P < 0.05 |
Univariate Analysis
The results of univariate analyses were shown in Table 2. Univariate analyses showed MHR, LDL, ALT, AST, BMI, SBP, DBP, fasting glucose, smoking, and drinking were positively associated with serum uric acid. We also found that age, TC, and exercise were not associated with serum uric acid while being female was a protective factor for elevated serum uric acid. Compared to males, serum uric acid decreased by 103.08 umol/L in females on average (P<0.0001).
Table 2
The results of univariate analysis
|
Statistics
|
Effect size (β)
|
P-value
|
MHR (umol/L, mean±SD)
|
0.31 ± 0.14
|
285.34 (239.17, 331.51)
|
<0.0001
|
AGE (years, mean ±SD)
|
49.31 ± 11.16
|
-0.57 (-1.22, 0.08)
|
0.0850
|
LDL-C (mmol/L, mean ±SD)
|
2.79 ± 0.70
|
16.92 (6.58, 27.26)
|
0.0014
|
TC (mmol/L, mean ±SD)
|
4.84 ± 0.89
|
3.68 (-4.46, 11.81)
|
0.3761
|
ALT (U/L, median, min-max)
|
24.26 ± 16.12
|
1.91 (1.48, 2.33)
|
<0.0001
|
AST (U/L, mean ±SD)
|
23.71 ± 8.47
|
2.51 (1.68, 3.35)
|
<0.0001
|
BMI (kg/m2, mean ±SD)
|
23.86 ± 3.31
|
10.44 (8.41, 12.48)
|
<0.0001
|
SBP (mmHg, mean ±SD)
|
123.31 ± 16.36
|
1.07 (0.64, 1.51)
|
<0.0001
|
DBP (mmHg, mean ±SD)
|
74.50 ± 11.34
|
2.16 (1.54, 2.78)
|
<0.0001
|
Fasting glucose (mmol/L, mean ±SD)
|
5.07 ± 0.92
|
8.93 (1.09, 16.78)
|
0.0259
|
SEX (n, %)
|
|
|
|
Male
|
369 (57.12%)
|
Reference
|
|
Female
|
277 (42.88%)
|
-103.08 (-115.35, -90.81)
|
<0.0001
|
Smoking status (n, %)
|
|
|
|
Nonsmokers
|
462 (71.63%)
|
Reference
|
|
Occasional smoking
|
37 (5.74%)
|
55.18 (24.69, 85.66)
|
0.0004
|
Smokers
|
146 (22.64%)
|
50.93 (33.99, 67.87)
|
<0.0001
|
Drinking state (n, %)
|
|
|
|
Nondrinkers
|
348 (53.95%)
|
Reference
|
|
Occasional drinking
|
185 (28.68%)
|
55.63 (39.88, 71.38)
|
<0.0001
|
Drinkers
|
112 (17.36%)
|
75.63 (56.83, 94.43)
|
<0.0001
|
Exercise status (n, %)
|
|
|
|
Low-intensity group
|
500 (77.40%)
|
0
|
Medium-intensity group
|
87 (13.47%)
|
15.54 (-5.80, 36.88)
|
0.1540
|
High-intensity group
|
59 (9.13%)
|
15.61 (-9.68, 40.89)
|
0.2269
|
LDL-C low-density lipoprotein cholesterol, TC total cholesterol, ALT alanine aminotransferase, AST aspartate transaminase, BMI body mass index, SBP systolic blood pressure, DBP diastolic blood pressure |
P < 0.05 |
The Relationship Between Mhr And Serum Uric Acid
To further demonstrate that MHR was an independent predictor of serum uric acid elevation, we performed the unadjusted and adjusted models with logistic regression analyses. As shown in Table 3, there was a positive correlation between MHR and serum uric acid in the unadjusted model (β = 285.340, 95% confidence interval (CI): 239.175~ 331.506, P<0.0001). A positive correlation also existed in the minimally adjusted model (adjusted for age and sex, β = 155.848, 95%CI: 109.641~ 202.055, P<0.0001) and fully adjusted model (adjusted for sex, age, LDL, TC, ALT, AST, BMI, SBP, DBP, GLU, smoking, drinking, exercise status, β = 128.77, 95%CI: 79.96~177.59, P<0.0001). We found significantly higher serum uric acid in MHR middle-level and high-level groups compared with the MHR low-level group among all the unadjusted and adjusted models (P for trend <0.001).
Table 3
Relationship between MHR and serum uric acid in different models
|
Non-adjusted (β, 95%CI, P)
|
minimally adjusted (β, 95%CI, P)
|
fully adjusted (β, 95%CI, P)
|
MHR (umol/L)
|
285.340 (239.175,331.506) <0.0001
|
155.848 (109.641,202.055) <0.0001
|
128.77 (79.96, 177.59) <0.0001
|
MHR grouping
|
|
|
|
Low-level
|
Reference
|
Reference
|
Reference
|
Middle-level
|
49.830 (33.603, 66.057) <0.0001
|
25.243 (10.240, 40.246) 0.0010
|
20.51 (5.51, 35.50) 0.0075
|
High-level
|
93.371 (77.145, 109.598) <0.0001
|
48.003 (31.911, 64.096) <0.0001
|
36.33 (19.42, 53.24) <0.0001
|
P for trend
|
<0.001
|
<0.001
|
<0.0001
|
Non-adjusted: we did not adjust other covariates |
Minimally adjusted model adjust for: SEX and age |
Fully adjusted model adjust for: sex, age, LDL, TC, ALT, AST, BMI, SBP, DBP, Fasting glucose, smoking and drinking status, exercise status |
P < 0.05 |
The Analyses Of Linear Relationship
After adjusted covariates, smooth fitting showed there was an approximately linear relationship between MHR and serum uric acid. As shown in Figure 1, after adjusted sex, age, LDL, TC, ALT, AST, BMI, SBP, DBP, fasting glucose, smoking, drinking, exercise status, the linear correlation coefficient of MHR on serum uric acid was 146.74 (95% CI: 96.16 ~ 197.33, p value<0.0001) (Table 4).
Table 4
analysis of the concentration-effect relationship
Independent variable
|
Effect size (β)
|
95% CI
|
P-value
|
MHR
|
146.74
|
96.16 to 197.33
|
<0.0001
|
Effect: uric acid Cause: MHR |
Adjusted: sex, age, LDL, TC, ALT, AST, BMI, SBP, DBP, fasting glucose, smoking status, drinking status, exercise status |
P < 0.05 |
The Results Of Subgroup Analyses
As shown in Table 5, the interactive test for smoking status was statistically significant (P = 0.0194). Compared with the nonsmokers, for per SD increase in MHR, serum uric acid rose by an average of 110.9 umol/L less in the occasional smokers and 134.1 umol/L less in smokers. There were no statistically significant in the interactive tests for sex, age, BMI, SBP, DBP, drinking, and exercise status (P were 0.5992, 0.6114, 0.6586, 0.5773, 0.0782, and 0.4333, 0.2961, respectively)
Table 5
Effect size of MHR on serum uric acid in established and exploratory subgroups
Characteristic
|
No of participants
|
Effect size (95%CI)
|
P (interaction)
|
SEX
|
|
|
0.5992
|
male
|
369
|
139.6 (82.2, 197.0)
|
|
female
|
277
|
167.0 (75.0, 259.1)
|
|
Age(year)
|
|
|
0.6114
|
\(\le\)50
|
349
|
156.96 (93.43, 220.49)
|
|
>50
|
297
|
135.62 (67.40, 203.83)
|
|
BMI (kg/m2)
|
|
|
0.6586
|
\(\le\)18.5
|
27
|
54.5 (-379.3, 488.3)
|
|
18.5<BMI\(\le\)24
|
312
|
174.8 (104.0, 245.7)
|
|
>24
|
307
|
139.5 (75.4, 203.7)
|
|
SBP (mmHg)
|
|
|
0.5773
|
\(\le\)120
|
321
|
160.7 (89.4, 232.0)
|
|
>129
|
325
|
137.0 (75.9, 198.1)
|
|
DBP (mmHg)
|
|
|
0.0782
|
\(\le\)80
|
452
|
174.7 (115.1, 234.2)
|
|
>80
|
194
|
96.1 (19.9, 172.3)
|
|
Smoking status
|
|
|
0.0194
|
Nonsmokers
|
462
|
202.6 (138.5, 266.6)
|
|
Occasional smoking
|
37
|
91.7 (-87.3, 270.7)
|
|
Smokers
|
146
|
68.5 (-10.7, 147.8)
|
|
Drinking status
|
|
|
0.4333
|
Nondrinkers
|
348
|
152.5 (80.4, 224.6)
|
|
Occasional drinking
|
185
|
175.6 (97.4, 253.7)
|
|
Drinkers
|
112
|
98.7 (4.5, 192.9
|
|
Exercise status
|
|
|
0.2961
|
Low-intensity group
|
500
|
149.7 (92.9, 206.5)
|
|
Medium-intensity group
|
87
|
197.2 (87.6, 306.9)
|
|
High-intensity group
|
59
|
171.5 (-50.8, 193.9)
|
|
Adjusted for sex, age, LDL, TC, ALT, AST, BMI, SBP, DBP, fasting glucose, smoking status, drinking status, and exercise status, but not the stratification variable |
P < 0.05 |