In either MHD patients and normal adults, the daily physical activity, human activity profile Maximum Activity Score and Adjusted Activity Score values were not significantly different in women as compared to men (Table 3). In MHD patients, the 6-MWT and the stair-climbing speed were significantly reduced in women. In normal adults, performance in the sit-to-stand test was significantly lower in women than in men. Moreover, male and female MHD patients, analyzed separately, each displayed significantly lower daily physical activity and human activity profile maximum activity and adjusted activity scores and reductions in all three physical performance tests as compared to normal men and women, respectively.
Table 3 Physical activity and physical performance by gender group
MHD patients N = 72 MHD:male vs. female Normal controls N = 39 Normals: male vs. female Males: MHD vs. normals Females: MHD vs. normals
Males N = 49 Females N = 23  p Males N = 23 Females N = 16  p  p  p
Age (years) 51.8 ± 13.0 53.8 ± 13.0 0.545 51.3 ± 14.7 50.6 ± 9.5 0.868 0.884 0.407
Vintage (months) 46.9 (46.7) 51.4 (72.4) 0.018 – – – – –
Physical activity
 Human activity profile
  Maximum activity score 84 (10) 82 (18) 0.155 92 (5) 89.5 (4) 0.472 <0.0001 <0.0001
  Adjusted activity score 76 (21) 69 (26) 0.319 91 (4) 88 (4) 0.285 <0.0001 <0.0001
 Time spent by monitor (%)
  Sleep or inactive 82.0 ± 5.8 81.7 ± 6.0 0.840 72.9 ± 6.1 72.7 ± 6.0 0.920 <0.0001 <0.0001
  Light activity 14.2 ± 4.4 14.9 ± 4.5 0.534 19.3 ± 4.3 21.0 ±4.6 0.245 <0.0001 0.0002
  ≥ Moderate activity 3.8 ± 2.0 3.3 ± 2.2 0.341 7.8 ± 3.3 6.4 ± 2.3 0.151 <0.0001 <0.0001
Average daily physical activity (vector magnitude)
  Daily physical activity (mean of 7 days) 421,539 (260,044) 365,050 (184,522) 0.398 644,556 (305,427) 596,642 (244,376) 0.435 <0.0001 <0.0001
  Day of HD 324,559 (203,547) 329,942 (135,789) 0.315 – – – – –
  1-day-post-HD 443,085 (261,536) 442,355 (211,902) 0.438 – – – – –
  2-days-post HD 398,185 (268,775) 360,273 (273,908) 0.887 – – – – –
Physical performance
 6-min walk distance (meters) 467.6 ± 98.9 385.3 ± 147.6 0.007 632.9 ± 60.7 595.5 ± 61.9 0.068 <0.0001 <0.0001
 Sit-to-stand test (cycles per 30 s) 16.5 ± 5.6 14.7 ± 4.2 0.175 28.1 ± 3.9 23.6 ± 6.3 0.009 <0.0001 <0.0001
 Stair-climbing test (seconds per 22 stairs) 13.5 ± 5.0 20.8 ± 17.2 0.008 9.6 ± 1.2 10.2 ± 1.0 0.109 <0.0001 0.008
Data expressed as mean ± standard deviation. Non-normally distributed data are expressed as median values with the interquartile range (IQR. i.e., the arithmetic difference between the 25th percentile value and the 75th percentile value) shown in parentheses