Average urinary flow rate and its association with handgrip strength

Figures & data

Figure 1. Relationship between the quartiles of urine flow rate and handgrip strength.

Table 1. Characteristics of study participants.

	Quartiles of urine flow rate
Characteristics of study participants	Q1 (<0.449) (n = 565)	Q2 (0.449–0.736) (n = 564)	Q3 (0.736–1.238) (n = 566)	Q4 (>1.238) (n = 563)	Total (n = 2258)	P Value
Continuous variables, mean (SD)
Hand grip strength (kg)	83.80 (19.80)	85.90 (19.43)	88.37 (18.73)	89.38 (18.48)	86.86 (19.22)	<0.001
Age (years)	49.09 (19.65)	48.12 (18.34)	47.27 (17.67)	44.91 (17.09)	47.35 (18.27)	0.001
BMI (kg/m^2)	27.93 (5.96)	27.99 (5.86)	28.58 (6.17)	28.43 (6.11)	28.23 (6.03)	0.186
Waist circumference (cm)	98.76 (16.47)	99.19 (16.44)	100.27 (15.14)	100.03 (16.51)	99.57 (16.15)	0.369
SBP (mmHg)	124.77 (17.19)	126.61 (18.60)	125.30 (16.43)	125.02 (15.96)	125.42 (17.06)	0.299
Albumin (g/dL)	4.33 (0.34)	4.38 (0.31)	4.37 (0.31)	4.43 (0.31)	4.38 (0.32)	<0.001
AST (U/L)	26.69 (13.11)	27.87 (19.04)	28.56 (28.77)	27.58 (13.02)	27.67 (19.57)	0.473
Serum TC (mg/dL)	181.07 (41.91)	186.86 (42.36)	187.78 (41.08)	186.88 (41.33)	185.64 (41.73)	0.033
Creatinine (mg/dL)	1.06 (0.40)	1.02 (0.30)	1.00 (0.20)	0.97 (0.30)	1.01 (0.31)	<0.001
Serum FG (mg/dL)	106.01 (39.49)	103.55 (35.23)	103.00 (42.75)	103.29 (44.23)	104.00 (40.56)	0.565
Categorical variables, n (%)
Race/ethnicity						0.813
Mexican American	67 (11.9)	57 (10.1)	51 (9.0)	54 (9.6)	229 (10.1)
Other Hispanic	45 (8.0)	56 (9.9)	50 (8.8)	55 (9.8)	206 (9.1)
Non-Hispanic white	181 (32.0)	197 (34.9)	243 (42.9)	237 (42.1)	858 (38.0)
Non-Hispanic black	187 (33.1)	156 (27.7)	135 (23.9)	108 (19.2)	586 (26.0)
Other	85 (15.0)	98 (17.4)	87 (15.4)	109 (19.4)	379 (16.8)
Disease
Arthritis	316 (29.4)	295 (24.5)	322 (24.8)	273 (20.5)	1206 (20.6)	<0.001
Congestive heart failure	23 (4.2)	19 (2.7)	17 (3.1)	10 (1.8)	69 (3.2)
Coronary heart disease	32 (5.8)	25 (4.6)	23 (4.2)	21 (3.9)	101 (4.6)	0.408
Angina pectoris	17 (3.1)	10 (1.8)	13 (2.4)	9 (1.7)	49 (2.2)	0.847
Heart attack	28 (5.1)	29 (5.3)	17 (3.1)	20 (3.7)	94 (4.3)	0.456
Smoking	296 (53.9)	290 (53)	289 (52.5)	283 (52.1)	1158 (52.9)	0.805

BMI: body mass index; SBP: systolic blood pressure; Serum FG: serum fasting glucose; Serum TC: serum total cholesterol; AST: aspartate aminotransferase; Serum CRP: serum C-reactive protein; Serum HDL: serum high-density lipoprotein.

^aValues were expressed as mean (standard deviation).

^bValues in the categorical variables were expressed as number (%).

Table 2. Regression coefficients of urine flow rate for hand grip strength.

Variables	Model 1		Model 2		Model 3		Model 4
	β (95% CI)	P Value	β (95% CI)	P Value	β (95% CI)	P Value	β (95% CI)	P Value
Urine flow rate	2.310 (1.357,3.263)	<0.001	1.518 (0.679, 2.357)	<0.001	1.382 (0.564, 2.200)	0.001	1.348 (0.530, 2.166)	0.001

Model 1 = unadjusted.

Model 2 = Model 1 +age, race/ethnicity.

Model 3 = Model 2 +BMI, serum fasting glucose, serum cholesterol, AST, serum albumin, serum creatinine, SBP, waist circumference.

Model 4 = Model 3 +histories of arthritis, congestive heart failure, coronary heart disease, angina, heart attack, and smoking.

Table 3. Association between the quartiles of urine flow rate and hand grip strength.

Variables	Models
	Model 1		Model 2		Model 3		Model 4
Quartiles of urine flow rate	β (95% CI)	P Value	β (95% CI)	P Value	β (95% CI)	P Value	β (95% CI)	P Value
Q2 vs. Q1	3.690 (1.161,6.219)	0.004	2.850 (0.626,5.074)	0.004	2.920 (0.769,5.07)	0.008	2.935 (0.781,5.089)	0.008
Q3 vs. Q1	5.170 (2.692,7.649)	<0.001	3.980 (1.800,6.161)	<0.001	3.881 (1.768,5.994)	<0.001	3.876 (1.763,5.989)	<0.001
Q4 vs. Q1	7.281 (4.854,9.707)	<0.001	5.022 (2.882,7.163)	<0.001	4.551 (2.466,6.635)	<0.001	4.546 (2.462,6.630)	<0.001

Model 1 = Unadjusted.

Model 2 = Model 1 +age, race/ethnicity.

Model 3 = Model 2 +BMI, serum fasting glucose, serum cholesterol, AST, serum albumin, serum creatinine, SBP, waist circumference.

Model 4 = Model 3 +histories of arthritis, congestive heart failure, coronary heart disease, angina, heart attack, and smoking.

Table 4. Association between the quartiles of urine flow rate and low muscle strength.

Variables	Low muscle strength
	Model 1		Model 2		Model 3		Model 4
Quartiles of urine flow rate	OR (95% CI)	P Value	OR (95% CI)	P Value	OR (95% CI)	P Value	OR (95% CI)	P Value
Q2 vs. Q1	0.662 (0.499–0.877)	0.004	0.654 (0.479–0.891)	0.007	0.677 (0.493–0.93)	0.016	0.668 (0.486–0.919)	0.013
Q3 vs. Q1	0.524 (0.393–0.699)	<0.001	0.533 (0.389–0.73)	<0.001	0.539 (0.39–0.746)	<0.001	0.535 (0.387–0.741)	<0.001
Q4 vs. Q1	0.423 (0.314–0.569)	<0.001	0.474 (0.343–0.655)	<0.001	0.492 (0.352–0.688)	<0.001	0.489 (0.350–0.684)	<0.001

Model 1 = Unadjusted.

Model 2 = Model 1 +age, race/ethnicity.

Model 3 = Model 2 +BMI, serum fasting glucose, serum cholesterol, AST, serum albumin, serum creatinine, SBP, waist circumference.

Model 4 = Model 3 +histories of arthritis, congestive heart failure, coronary heart disease, angina, heart attack, and smoking.