Examining the Links Between Physical Activity, Sitting Time, and Renal Function in T2DM Patients

Figures & data

Table 1 Demographic Characteristics of Participants

	Total
	n = 1761
Age, mean ± SD, years	58.6 ±12.2
Gender, male, n (%)	965 (54.8)
Marital status, married, n (%)	1461 (93.2)
Education level, n (%)
Illiterate	351 (19.9)
Primary	394 (22.4)
Junior and Senior	621 (35.3)
College degree or above	395 (22.4)
Residence, urban, n (%)	1102 (62.6)
Smoking, yes, n (%)	396 (22.5)
Alcohol use, yes, n (%)	368 (20.9)
BMI, mean ± SD, kg/m2	25.0±14.2
Other chronic diseases, yes, n (%)	1160 (65.9)
T2DM complications, yes, n (%)	1059 (60.1)
Disease duration, mean ± SD, years	8.4±7.6
HbA1c, <7%, n (%)	338 (19.2)
TG, mean ± SD, mmol/L	2.2±2.0
TC, mean ± SD, mmol/L	4.7±11.7
HDL, mean ± SD, mmol/L	1.1±0.3
LDL, mean ± SD, mmol/L	2.6±0.8
Urea, mean ± SD, mmol/L	5.7±1.6
Sitting time, mean ± SD, hour	4.8±2.6
Physical activity, n (%)
Never	588 (33.4)
2–3 times/month	199 (11.3)
1–2 times/week	273 (15.5)
More than 3 times/week	701 (39.8)
eGFR, mL/min/1.73m^2	123.8±39.7

Abbreviations: SD, standard deviation; T2DM, type 2 diabetes mellitus; BMI, body mass index; HbA1c, Glycated hemoglobin; TG, Triglyceride; TC, Total cholesterol; HDL, High-density lipoprotein; LDL, Low-density lipoprotein; eGFR, estimated glomerular filtration rate.

Table 2 Correlation Matrix (n = 1761)

	Mean	SD	eGFR	Physical Activity	Sitting Time
eGFR	123.8	39.7	1
Physical activity	4.8	2.6	0.07**	1
Sitting time	2.6	1.3	−0.05*	−0.12**	1

Notes: *p < 0.05, **p < 0.001.

Abbreviation: SD, standard deviation.

Table 3 Linear Regression Model for Interaction Between Physical Activity and Sitting Time on eGFR (n = 1761)

Variables	Model 1		Model 2		Model 3
	P value	B (95% CI)	P value	B (95% CI)	P value	B (95% CI)
Physical activity	0.020	1.69 (0.26, 3.11)	0.010	1.78 (0.42, 3.14)	0.033	2.76 (0.22, 5.30)
Sitting time	0.048	−0.73 (−1.45, −0.01)	0.046	−0.68 (−1.34, −0.01)	0.950	−0.04 (−1.46, 1.37)
Age	NA	NA	<0.001	−0.94 (−1.12, −0.77)	<0.001	−0.95 (−1.128, −0.78)
Gender (reference=female)	NA	NA	<0.001	−9.18 (−13.43, −4.92)	<0.001	−9.17 (−13.43, −4.92)
Marital status (reference=unmarried)	NA	NA	0.561	−2.04 (−8.91, 4.84)	0.584	−1.92 (−8.80, 4.96)
Education (reference=Illiterate)	NA	NA	0.062	2.05 (−0.10, 4.20)	0.065	2.03 (−0.12, 4.18)
Residence (reference=rural)	NA	NA	0.391	1.82 (−2.34, 5.99)	0.401	1.78 (−2.39, 5.96)
Smoking (reference=no)	NA	NA	0.986	0.04 (−4.84, 4.93)	0.998	0.01 (−4.88, 4.89)
Alcohol use (reference=no)	NA	NA	0.049	4.96 (0.01, 9.91)	0.049	4.97 (0.02, 9.92)
BMI	NA	NA	<0.001	−5.14 (−7.46, −2.81)	<0.001	−5.12 (−7.47, −2.81)
Other chronic diseases (reference=no)	NA	NA	<0.001	−9.12 (−12.93, −5.31)	<0.001	−9.08 (−12.88, −5.27)
Duration of disease	NA	NA	<0.001	−0.49 (−0.75, −0.23)	<0.001	−0.49 (−0.75, −0.23)
Fasting blood glucose	NA	NA	0.109	−0.33 (−0.73, 0.07)	0.114	−0.33 (−0.73, 0.08)
T2DM complications (reference=no)	NA	NA	0.956	−0.10 (−3.82, 3.61)	0.949	−0.12 (−3.83, 3.59)
HbA1c	NA	NA	<0.001	2.99 (2.10, 3.88)	<0.001	2.99 (2.10, 3.88)
TG	NA	NA	0.575	−0.25 (−1.14, 0.63)	0.547	−0.27 (−1.16, 0.61)
TC	NA	NA	0.783	0.02 (−0.12, 0.16)	0.832	0.02 (−0.13, 0.16)
HDL	NA	NA	0.002	9.90 (3.78, 16.03)	0.002	9.80 (3.67, 15.93)
LDL	NA	NA	0.006	−2.90 (−4.95, −0.85)	0.007	−2.82 (−4.88, −0.77)
Urea	NA	NA	<0.001	−9.50 (−10.52, −8.49)	<0.001	−9.48 (−10.50, –8.50)
Sitting time×physical activity	NA	NA	NA	NA	0.324	−0.74 (−0.25, 0.24)
R^2	0.003		0.310		0.195

Notes: Model l = physical activity or sitting time separately; Model 2 = Model l + covariates (age, gender, marital status, education, residence, smoking, alcohol use, BMI, other chronic diseases, disease duration, fasting blood glucose, T2DM complications, HbA1c, TG, TC, HDL, LDL, urea); Model 3 = Model 2 + interaction between sedentary time and physical activity.

Abbreviations: 95% CI, 95% confidence interval; NA, not apply.

Table 4 The Mediating Effect of Physical Activity on the Relationship Between Sitting Time and eGFR*

Effect	β	SE	P value	Bias-Corrected 95% CI
				Lower	Upper
Total effect	−0.609	0.307	0.047	−1.212	−0.006
Indirect Effects	−0.098	0.050	0.046	−0.215	−0.024
Direct Effects	−0.511	0.309	0.098	−1.117	0.094

Notes: *After controlling for age, gender, marital status, education, residence, smoking, alcohol use, BMI, fasting blood glucose, other chronic disease, disease duration, complications of diabetes, HbA1c, TG, TC, HDL, LDL, urea.

Table 5 The Mediation Model of Physical Activity Stratified by Age*

Effect	β	SE	P-value	Bias-Corrected 95% CI
				Lower	Upper
<45 years old
Total effect	−1.208	1.122	0.283	−3.420	1.004
Indirect Effects	−0.100	0.156	0.521	−0.631	0.094
Direct Effects	−1.108	1.121	0.324	−3.319	1.103
45–59 years old
Total effect	−0.563	0.515	0.275	−1.575	0.449
Indirect Effects	−0.024	0.054	0.589	−0.206	0.039
Direct Effects	−0.539	0.517	0.297	−1.554	0.476
≥60 years old
Total effect	−1.036	0.501	0.039	−2.019	−0.052
Indirect Effects	−0.237	0.093	0.013	−0.467	−0.089
Direct Effects	−0.799	0.505	0.113	−1.789	0.192

Notes: *After controlling for gender, marital status, education, residence, smoking, alcohol use, BMI, fasting blood glucose, other chronic disease, disease duration, complications of diabetes, HbA1c, TG, TC, HDL, LDL, urea.