**3.7 Serum alkaline phosphatase of subjects**

58 Chronic Kidney Disease

n = 52

37 (71%)

12 (23%)

3 (6%)

The mean serum phosphate in the CRF group was 6.1 + 2.0mg/dl, and this was significantly higher than the mean serum phosphate of 3.2 + 0.6mg/dl in the control group (p<0.05). Table 7 shows the pattern of serum phosphate in both the CRF and control groups. In the CRF group, 41 (79%) patients had hyperphosphataemia, while 11 (21%) had normal serum phosphate levels. No patient had hypophosphataemia. In the control group, all the 40 (100%) patients had normal serum phosphate levels. There was insignificant but positive correlation between serum phosphate and creatinine clearance (r = 0.1) and bone pain (r =

> CRF group n = 52

11 (21%)

41 (79%)

Amongst the CRF patients with serum alkaline phosphatase of <25iu/l, the mean serum phosphate was 5.1 + 0.9mg/dl, while in the group with serum alkaline phosphatase of 25 – 95iu/l, serum phosphate was 6.5 + 1.2mg/dl, and in the group with serum alkaline phosphatase of >95iu/l the mean serum phosphate was 6.2 + 1.4mg/dl. Thus, there was a weak but negative correlation between serum phosphate and total serum alkaline phosphatase (r – 0.15), such that when total serum alkaline phosphatase was increasing, the

Amongst the CRF patients with creatinine clearance of >30mls/min, the mean serum phosphate was 4.4 + 1.2mg/dl, while in the groups with creatinine clearance of 15 – 29mls/min and <15mls/min (ESRD), the mean serum phosphate was 6.6 + 1.1mg/dl and 6.2 + 1.3mg/dl respectively. As the creatinine clearance tended towards ESRD, the serum phosphate rises. There was a positive correlation between serum phosphate and creatinine


Control group

n = 40

1 (3%)

39 (97%)

Control group

n = 40

40 (100%)




Serum Calcium (mg/dl) CRF group

Table 6. The distribution of subjects according to serum calcium.

Hypocalcaemia (<8.5mg/dl) Normal levels (8.5 – 10.5mg/dl) Hypercalcaemia (>10.5mg/dl)

0.4). (See Table 7)

(mg/dl)

(<2.4mg/dl) Normal phosphate Level (2.4 - 4.5mg/dl) Hyperphosphataemia

(>4.5mg/dl)

Serum phosphate

Hypophosphataemia

Table 7. Pattern of serum phosphate in subjects.

serum phosphate also increased.

clearance (r = 0.10).

**3.6 Serum phosphate of subjects** 

The mean total serum alkaline phosphatase in the CRF group was 129.4 + 21.6iu/l, while that of the control was 43.73 + 8.3iu/l. There was a statistically significant difference between both means (p<0.05). 41 (79%) of the CRF group had elevated total serum alkaline phosphatase levels, 8 (15%) had normal levels, 3 (6%) had low levels, while all controls had normal levels. Of the 41 CRF patients that had elevated total serum alkaline phosphatase levels, all (100%) had >50% of their alkaline phosphatase levels, from bone isoenzyme (bone specific alkaline phosphatase). Only 1 (2%) CRF patient had radiological evidence of ROD (Rugger Jersey Spine). Total serum alkaline phosphatase correlated positively with creatinine clearance (r = 0.06) and bone pain (r = 0.4).

Amongst the CRF group with creatinine clearance of >30mls/min the mean total alkaline phosphatase was 105 + 6.1iu/l, while in the groups with creatinine clearance of 15 – 29mls/min and <15mls/min (ESRD), the mean alkaline phosphatase were 124 + 4.6iu/l and 143 + 5.6iu/l respectively (see Table 8).


Table 8. Distribution of CRF and control groups according to serum alkaline phosphatase.
