Table 1: Socio-demographic, clinical and laboratory characteristics and in-hospital outcomes in older hip fracture patients by serum urea levels on admission.
| Variables
|
All patients
(n=1819)
|
Urea>7.5 mmol/L (n=800) |
Urea≤7.5 mmol/L (n=1019) |
P Value |
| Age, years |
|
| Females |
83.4±7.7 |
84.9±7.3 |
82.3±7.9 |
<0.001 |
| Males |
80.6±9.0 |
83.4±7.2 |
78.0±9.7 |
<0.001 |
| Both genders |
82.8±8.1 |
84.5±7.3 |
81.4±8.5 |
<0.001 |
| Age >75 years, n (%) |
1511(83.1) |
719(89.9) |
792(77.7) |
<0.001 |
| Age >80 years, n (%) |
1288(70.8) |
629(78.6) |
659(64.7) |
<0.001 |
| Males/Females, n |
429/1390 |
206/594 |
223/796 |
0.054 |
| From RCF, n (%) |
636(35.0) |
300(37.5) |
336(33.0) |
0.044 |
| CKD, n (%) |
789(43.4) |
566(70.8) |
223(21.9) |
<0.001 |
| CAD, n (%) |
49(26.9) |
261(32.6) |
229(22.5) |
<0.001 |
| MI, n (%) |
133(7.3) |
84(10.5) |
49(4.8) |
<0.001 |
| HT, n (%) |
937(51.5) |
451(56.4) |
486(47.7) |
<0.001 |
| Anaemia: |
|
| Hb<110g/L, n (%) |
355(19.5) |
194(24.3) |
161(15.8) |
<0.001 |
| Hb<120g/L, n (%) |
699(38.4) |
370(46.3) |
329(32.3) |
<0.001 |
| CVA, n (%) |
219(12.0) |
83(10.4) |
136(13.3) |
<0.053 |
| DM, n (%) |
175(9.6) |
92(11.5) |
83(8.1) |
0.016 |
| Smoker, n (%) |
100(5.5) |
33(4.1) |
67(6.6) |
0.024 |
| Alcohol+, n (%) |
92(5.1) |
25(3.1) |
68(6.6) |
0.001 |
| Urea, mmol/L |
8.5±7.4 |
12.4±9.8 |
5.4±1.4 |
<0.001 |
| Creatinine, µmol/L |
92.9±60.0 |
119.0±80.3 |
72.3±20.5 |
<0.001 |
| GFR, ml/min/1.73m2
|
62.5±22.1 |
49.1±20.5 |
72.9±17.2 |
<0.001 |
| PTH, pmol/L |
8.5±7.4 |
10.4±9.1 |
7.1±5.3 |
<0.001 |
| 25(OH)D, mmol/L |
48.3±28.8 |
50.3±29.2 |
46.7±28.4 |
0.016 |
| ALP, IU/L |
100.8±70.7 |
106.5±86.7 |
96.3±54.7 |
0.003 |
| Bilirubin, µmol/L |
12.4±8.1 |
11.7±6.8 |
12.9±8.9 |
0.003 |
| Outcomes: |
|
| LOS, days |
19.0±22.3 |
20.5±25.7 |
17.8±19.2 |
0.011 |
| LOS>20 days, % |
28.4 |
31.2 |
26.2 |
0.021 |
| HPIR, % |
16.5 |
22.1 |
12.1 |
0.012 |
| Died, % |
6.0 |
9.4 |
3.3 |
<0.001 |
Abbreviations: RCF, residential care facility (permanent); CKD, chronic kidney disease (GFR<60 ml/min/1.73m2); CAD, coronary artery disease; MI, history of myocardial infarction; CVA, cerebrovascular accident; DM, diabetes mellitus type 2; Hb, haemoglobin; Alcohol+, alcohol over-user (≥3 drinks/week); GFR, glomerular filtration rate; PTH, parathyroid hormone; 25(OH)D, 25(OH) vitamin D; ALP, alkaline phosphatase; LOS, length of hospital stay; HPIR, high postoperative inflammatory response (C-reactive protein >150mg/L after the 3rd postoperative day).
Notes: Continuous data are expressed as mean ± SD and categorical data as number (%). Only statistically significant associations shown. There was no significant differences between patients with and without elevated serum urea on admission in prevalence of hip fracture type (cervical fracture: 51.0% vs. 55.2%, p=0.074), dementia (33.7% vs. 31.5%, p=0.335), chronic obstructive pulmonary disease (11.7% vs. 11.4%, p=0.900), transient cerebral ischaemic attack (7.8% vs. 7.9%, p=0.956), Parkinson’s disease (4.9% vs. 4.7%, p=0.855), walking aids users (40.0% vs.36.1%, p=0.077) or ex- smokers (12.6 vs.13.2%, p=0.713). There were also no significant differences between the two groups with respect to mean values of albumin (36.9 vs. 36.8g/L, p=0.921), alanine aminotransferase (ALT, 23.6 vs.25.9IU/L, p=0.471), gamma-glutamyl transferase (GGT, 55.8 vs. 57.8 IU/L, p=0.696), GGT/ALT ratio (2.9 vs.2.9, p=0.970), transferrin saturation (10.9 vs. 10.9%, p=0.948) and CRP (99.8 vs. 89.2mg/L, p=0.338).