Table 1 shows that in 2516 men and 6664 women, older age, higher body fat percentage, waist circumference, BMI and lower percentage of current alcohol were associated with higher glycaemia levels from normorglycaemia to T2DM (P from < 0.001 to 0.003). There were also significant differences in physical activity, education and health status in women and smoking status in men with poorer status in T2DM group (P from < 0.001 to 0.002). The characteristics by sex-specific quintiles of RGS max are shown in the Supplementary table 1.
Table 2 shows that, after adjusting for age, education, smoking status, alcohol use, physical activity, body fat percentage and waist circumference, in men, women, and the total participants, RGS max declined from normoglycaemia to prediabetes (from IFG only, to IGT only, then to IFG + IGT), then to known/newly diagnosed T2DM groups (P for trend = 0.02, 0.03 and 0.005, respectively). Although the associations of glycemic status with other measures of grip strength (i.e., RGS mean, RGS left, RGS right and AGS) were not statistically significant in women (P for trend from 0.07 to 0.17), the associations remained significant in men (P for trend from 0.01 to 0.03) and total participants (P for trend from 0.005 to 0.03).
Table 2
Grip strength by different diabetes status in 2516 men and 6664 women
| Normoglycaemia | IFG only | IGT only | IFG + IGT | T2DM | Known T2DM | P for trend† |
Men |
Number of subjects | 1271 | 224 | 363 | 150 | 209 | 299 | |
Relative grip strength max† | 1.38 (1.34, 1.42) | 1.37 (1.33, 1.40) | 1.36 (1.32, 1.39) | 1.35 (1.30, 1.39) | 1.33 (1.29, 1.38) | 1.32 (1.27, 1.37) | 0.02 |
Relative grip strength mean† | 1.30 (1.27, 1.34) | 1.29 (1.26, 1.33) | 1.28 (1.25, 1.31) | 1.27 (1.24, 1.31) | 1.26 (1.22, 1.30) | 1.25 (1.21, 1.29) | 0.01 |
Relative grip strength left† | 1.30 (1.26, 1.33) | 1.28 (1.25, 1.32) | 1.27 (1.23, 1.31) | 1.26 (1.22, 1.30) | 1.25 (1.21, 1.29) | 1.24 (1.19, 1.29) | 0.01 |
Relative grip strength right† | 1.31 (1.27, 1.35) | 1.30 (1.27, 1.33) | 1.29 (1.26, 1.33) | 1.28 (1.25, 1.32) | 1.27 (1.23, 1.31) | 1.26 (1.22, 1.31) | 0.01 |
Absolute grip strength, kg†† | 32.76 (31.88, 33.65) | 32.52 (31.68, 33.36) | 32.27 (31.43, 33.12) | 32.03 (31.14, 32.92) | 31.79 (30.80, 32.77) | 31.54 (30.44, 32.64) | 0.03 |
Women |
Number of subjects | 3395 | 487 | 993 | 391 | 558 | 840 | |
Relative grip strength max† | 0.91 (0.89, 0.92) | 0.90 (0.89, 0.92) | 0.90 (0.89, 0.91) | 0.90 (0.88, 0.91) | 0.89 (0.87, 0.91) | 0.88 (0.86, 0.90) | 0.03 |
Relative grip strength mean† | 0.86 (0.84, 0.87) | 0.85 (0.84, 0.87) | 0.85 (0.84, 0.86) | 0.85 (0.84, 0.86) | 0.85 (0.83, 0.86) | 0.84 (0.83, 0.86) | 0.17 |
Relative grip strength left† | 0.85 (0.84, 0.86) | 0.85 (0.83, 0.86) | 0.84 (0.83, 0.86) | 0.84 (0.83, 0.85) | 0.84 (0.82, 0.85) | 0.83 (0.81, 0.85) | 0.15 |
Relative grip strength right† | 0.86 (0.85, 0.88) | 0.86 (0.85, 0.87) | 0.86 (0.85, 0.87) | 0.86 (0.84, 0.87) | 0.85 (0.84, 0.87) | 0.85 (0.83, 0.87) | 0.15 |
Absolute grip strength, kg†† | 20.82 (20.49, 21.14) | 20.72 (20.43, 20.01) | 20.62 (20.33, 20.91) | 20.52 (20.20, 20.85) | 20.42 (20.04, 20.81) | 20.33 (19.87, 20.78) | 0.07 |
Total |
Number of subjects | 4666 | 711 | 1356 | 541 | 767 | 1139 | |
Relative grip strength max$ | 1.02 (1.01, 1.03) | 1.01 (1.00, 1.02) | 1.00 (1.00, 1.01) | 1.00 (0.99, 1.01) | 0.99 (0.98, 1.00) | 0.99 (0.97, 1.00) | 0.005 |
Relative grip strength mean$ | 0.96 (0.95, 0.97) | 0.95 (0.95, 0.96) | 0.95 (0.94, 0.96) | 0.94 (0.94, 0.95) | 0.94 (0.93, 0.95) | 0.94 (0.92, 0.95) | 0.03 |
Relative grip strength left$ | 0.95 (0.94, 0.96) | 0.94 (0.94, 0.95) | 0.94 (0.93, 0.94) | 0.93 (0.92, 0.94) | 0.93 (0.91, 0.94) | 0.92 (0.91, 0.94) | 0.02 |
Relative grip strength right$ | 0.97 (0.96, 0.98) | 0.97 (0.96, 0.97) | 0.96 (0.95, 0.97) | 0.96 (0.95, 0.97) | 0.95 (0.94, 0.96) | 0.95 (0.93, 0.96) | 0.02 |
Absolute grip strength, kg$$ | 23.79 (23.58, 24.06) | 23.67 (23.50, 23.84) | 23.54 (23.38, 23.71) | 23.42 (23.21, 23.63) | 23.30 (23.01, 23.58) | 23.17 (22.81, 23.53) | 0.008 |
Results were shown as mean (95% confidence interval), except for numbers. |
†: Adjusted for age, education, smoking status, alcohol use, physical activity, body fat percentage and waist circumference. |
††: Adjusted for age, education, smoking status, alcohol use, physical activity, body fat percentage and waist circumference and body mass index (BMI). |
$: Adjusted for age, sex, education, smoking status, alcohol use, physical activity, body fat percentage and waist circumference. |
$$: Adjusted for age, sex, education, smoking status, alcohol use, physical activity, body fat percentage and waist circumference and BMI. |
IFG, impaired fasting glucose; IGT, impaired glucose tolerance; T2DM, type 2 diabetes; relative grip strength max, maximal of the average of the right or the left grip strength divided by BMI; Relative grip strength mean, the mean of the average of both the right and the left grip strength divided by BMI; Relative grip strength left, the average of the left grip strength divided by BMI; Relative grip strength right, the average of the right grip strength divided by BMI; Absolute grip strength, maximal of the average of the right or the left grip strength. |
Table 3 shows that, after similar adjustment, in participants with normoglycaemia, fasting glucose was inversely associated with all measures of RGS and AGS in women (P for trend from 0.002 to 0.03). In women, the adjusted β (95% CI) was − 0.04 (-0.08, -0.005) for RGS max, -0.04 (-0.07, -0.02) for RGS mean, -0.05 (-0.08, -0.02) for RGS left, -0.04 (-0.07, -0.006) for RGS right and − 0.98 (-1.74, -0.22) for AGS. However, no association of fasting glucose with grip strength was found in men, when fasting glucose was analyzed as quartiles or continuous (P for trend from 0.67 to 0.88). As the associations did not vary by sex (P for sex interaction from 0.13 to 0.92), we also conducted analysis in total participants and found consistently inverse associations between fasting glucose and all measures of grip strength (P for trend from 0.006 to 0.049). No association between 2hPG and measures of grip strength in normoglycaemic group was found (Supplementary table 2).
Table 3. Grip strength by fasting glucose (in quartiles and as continuous, mmol/l) in 1271 men and 3394 women with normoglycaemia
|
Quartile of fasting glucose in normoglycaemia, mmol/l
|
Adjusted β†
|
P for trend
|
|
1st
|
2nd
|
3rd
|
4th
|
Men
|
Number of subjects
|
314
|
310
|
319
|
328
|
-
|
-
|
Fasting glucose, mmol/l
|
4.39 (4.35, 4.42)
|
4.82 (4.81, 4.83)
|
5.07 (5.07, 5.08)
|
5.40 (5.38, 5.42)
|
-
|
-
|
Post-load glucose, mmol/l†
|
5.94 (5.76, 6.13)
|
6.14 (5.97, 6.30)
|
6.26 (6.10, 6.43)
|
6.42 (6.24, 6.60)
|
0.51 (0.33, 0.68)***
|
<0.001
|
Relative grip strength max†
|
1.43 (1.37, 1.49)
|
1.43 (1.37, 1.48)
|
1.43 (1.37, 1.48)
|
1.43 (1.37, 1.49)
|
-0.004 (-0.06, 0.05)
|
0.88
|
Relative grip strength mean†
|
1.35 (1.30, 1.41)
|
1.35 (1.30, 1.40)
|
1.35 (1.30, 1.39)
|
1.35 (1.30, 1.40)
|
-0.01 (-0.06, 0.04)
|
0.70
|
Relative grip strength left†
|
1.35 (1.29, 1.41)
|
1.34 (1.29, 1.40)
|
1.34 (1.28, 1.40)
|
1.34 (1.28, 1.40)
|
-0.01 (-0.07, 0.05)
|
0.67
|
Relative grip strength right†
|
1.36 (1.31, 1.41)
|
1.36 (1.31, 1.40)
|
1.36 (1.31, 1.40)
|
1.35 (1.31, 1.40)
|
-0.008 (-0.05, 0.04)
|
0.75
|
Absolute grip strength, kg††
|
33.27 (31.92, 34.61)
|
33.21 (32.03, 34.40)
|
33.18 (32.00, 34.36)
|
33.14 (31.85, 34.42)
|
-0.14 (-1.39, 1.12)
|
0.83
|
Women
|
Number of subjects
|
840
|
833
|
844
|
877
|
-
|
-
|
Fasting glucose, mmol/l
|
4.46 (4.45, 4.48)
|
4.82 (4.82, 4.82)
|
5.07 (5.07, 5.08)
|
5.37 (5.37, 5.38)
|
-
|
-
|
Post-load glucose, mmol/l†
|
5.89 (5.82, 5.97)
|
6.07 (6.01, 6.13)
|
6.19 (6.13, 6.25)
|
6.34 (6.26, 6.41)
|
0.47 (0.37, 0.57)***
|
<0.001
|
Relative grip strength max†
|
0.95 (0.93, 0.98)
|
0.94 (0.92, 0.96)
|
0.93 (0.91, 0.95)
|
0.92 (0.89, 0.94)
|
-0.04 (-0.08, -0.005)*
|
0.03
|
Relative grip strength mean†
|
0.90 (0.88, 0.92)
|
0.89 (0.87, 0.90)
|
0.87 (0.86, 0.89)
|
0.86 (0.84, 0.88)
|
-0.04 (-0.07, -0.02)**
|
0.002
|
Relative grip strength left†
|
0.90 (0.87, 0.92)
|
0.88 (0.86, 0.90)
|
0.87 (0.85, 0.89)
|
0.85 (0.83, 0.88)
|
-0.05 (-0.08, -0.02)**
|
0.003
|
Relative grip strength right†
|
0.91 (0.88, 0.93)
|
0.89 (0.87, 0.91)
|
0.88 (0.86, 0.90)
|
0.87 (0.85, 0.89)
|
-0.04 (-0.07, -0.006)*
|
0.02
|
Absolute grip strength, kg††
|
21.26 (20.70, 21.83)
|
20.89 (20.45, 21.33)
|
20.64 (20.19, 21.10)
|
20.34 (19.77, 20.90)
|
-0.98 (-1.74, -0.22)*
|
0.01
|
Total
|
Number of subjects
|
1154
|
1143
|
1163
|
1205
|
|
|
Fasting glucose, mmol/l
|
4.44 (4.43, 4.46)
|
4.82 (4.816, 4.82)
|
5.07 (5.07, 5.08)
|
5.38 (5.37, 5.39)
|
-
|
-
|
Post-load glucose, mmol/l$
|
5.88 (5.82, 5.93)
|
6.06 (6.03, 6.09)
|
6.18 (6.15, 6.22)
|
6.33 (6.28, 6.38)
|
0.48 (0.40, 0.57) ***
|
<0.001
|
Relative grip strength max$
|
1.06 (1.04, 1.08)
|
1.05 (1.04, 1.06)
|
1.04 (1.03, 1.06)
|
1.03 (1.02, 1.05)
|
-0.03 (-0.06, -0.00008)*
|
0.049
|
Relative grip strength mean$
|
1.01 (0.99, 1.02)
|
0.99 (0.98, 1.00)
|
0.98 (0.97, 0.99)
|
0.97 (0.96, 0.99)
|
-0.04 (-0.06, -0.01)**
|
0.006
|
Relative grip strength left$
|
1.00 (0.98, 1.01)
|
0.98 (0.97, 0.99)
|
0.97 (0.96, 0.98)
|
0.96 (0.94, 0.98)
|
-0.04 (-0.07, -0.01)**
|
0.008
|
Relative grip strength right$
|
1.01 (1.00, 1.03)
|
1.00 (0.99, 1.01)
|
1.00 (0.99, 1.01)
|
0.99 (0.97, 1.00)
|
-0.03 (-0.06, -0.003)*
|
0.03
|
Absolute grip strength, kg$$
|
24.23 (23.82, 24.63)
|
23.97 (23.72, 24.22)
|
23.80 (23.54, 24.06)
|
23.59 (23.21, 23.97)
|
-0.68 (-1.33, -0.02)*
|
0.04
|
Results were shown as mean (95% confidence interval), except for numbers.
Relative grip strength max, maximal of the average of the right or the left grip strength divided by body mass index (BMI); Relative grip strength mean, the mean of the average of both the right and the left grip strength divided by BMI; Relative grip strength left, the average of the left grip strength divided by BMI; Relative grip strength right, the average of the right grip strength divided by BMI; Absolute grip strength, maximal of the average of the right or the left grip strength.
P values for sex interaction with fasting glucose in terms of all measures of grip strength were from 0.13 to 0.92.
†: Adjusted for age, education, smoking status, alcohol use, physical activity, body fat percentage and waist circumference.
††: Adjusted for age, education, smoking status, alcohol use, physical activity, body fat percentage and waist circumference and BMI.
$: Adjusted for age, sex, education, smoking status, alcohol use, physical activity, body fat percentage and waist circumference.
$$: Adjusted for age, sex, education, smoking status, alcohol use, physical activity, body fat percentage and waist circumference and BMI.
*: P<0.05; **: P<0.01; ***: P<0.001.
In participants without T2DM, in women, increasing fasting glucose was associated with lower RGS max after full adjustment (P < 0.001 for trend), with the RGS max (95% CI) being 0.88 (0.86, 0.90) in the highest decile and 0.95 (0.93, 0.97) in the lowest. In men, there was similar trend between fasting glucose and RGS max but the association was not statistically significant (P = 0.22) (Fig. 1). The association of 2hPG with RGS max were not significant in both men and women (P value for trend = 0.35 and 0.39, respectively) (Supplementary Fig. 1).