**3.5 Serum calcium of subjects**

The mean serum calcium in the CRF and control groups was 6.9 + 2.3mg/dl and 9.12 + 0.53mg/dl respectively. This difference between the means was statistically significant (p<0.05).

Table 6 shows the pattern of serum calcium concentration in the study population. In the CRF group, 37 (71%) patients had hypocalcaemia (<8.5mg/dl), 3 (6%) had hypercalcaemia (>10.5mg/dl, while 12 (23%) had normal calcium levels (8.5 – 10.5mg/dl). In the control group, 39 (97%) patients had normal calcium levels, while only 1 (3%) had hypocalcaemia. None in the control group had hypercalcaemia. There was a weak positive correlation between serum calcium and total alkaline phosphate in the CRF group (r = 0.04), such that as the serum alkaline phosphate was increasing, the serum calcium was decreasing. Amongst the CRF patients with total serum alkaline phosphate of <25iu/l, the mean serum calcium was 6.4 + 1.6mg/dl, while in the group with total serum alkaline phosphate of 25 – 95iu/l, the mean serum calcium was 7.9 + 3.0mg/dl, and in the group with total serum alkaline phosphate of >95iu/l, the mean serum calcium was 6.8 + 1.8mg/dl. There was an insignificant correlation between serum calcium and creatinine clearance (r = 0.007). Amongst the CRF patients with creatinine clearance of <15mls/min, the mean serum calcium was 5.2 + 2.4mg/dl, while in the group that had creatinine clearance of 15 – 29mls/min, the mean serum calcium was 6.3 + 2.1mg/dl, and in the group with creatinine clearance of >30mls/min, the mean serum calcium was 8.4 + 1.6mg/dl. Mean serum calcium tends to be lower in ESRD patients (see table 6).

The Prevalence of Renal Osteodystrophy in

**3.7 Serum alkaline phosphatase of subjects** 

creatinine clearance (r = 0.06) and bone pain (r = 0.4).

**3.8 Calcium and phosphate products of CRF subjects** 

143 + 5.6iu/l respectively (see Table 8).

Total serum alkaline phosphatase (iu/l)

Increased levels (>95iu/l) Normal levels (25 – 95iu/l Decreased levels (<25iu/l)

ROD on postmortem bone biopsy.

**3.9 Urinary calcium excretion in study group** 

Chronic Renal Failure Patients in Urban Niger Delta of Nigeria 59

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

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

> CRF group, n = 52 Frequency (%)

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

The mean calcium x phosphate products in the CRF group was 42.8 + 21.6mg2/dl2 while that of the control was 28.21 + 2.4mg2/dl2. There was a statistically significant difference in both means (p<0.05). Table 9 shows distribution of calcium x phosphate product amongst the CRF patients. 3 (5%) of the CRF patients had calcium x phosphate product >70mg2/dl2. This was made up of 2 (66%) males and 1 (34%) female. 6 (11%) patients had their calcium x phosphate product between 52 – 70mg2/dl2. This was made up of 2 (33%) males and 4 (67%) females. 43 (82%) patients had their calcium x phosphate products <52mg2/dl2. This was made up of 26 (60%) males and 17 (40%) females. All 3 patients who had calcium x phosphate product >70mg2/dl2 died during the period of study and showed evidence of

Normal Ca x P04 product = <70mg2/dl2.

The mean 24 hours urinary calcium in the CRF group was 68.4+ 12.8mg/dl, and 162 + 40.4mg/dl in the control group. This difference in means is statistically significant (p<0.05). There was an insignificant correlation between 24hours urinary calcium and creatinine clearance, and serum calcium (r =-0.16) and (r =0.02) respectively. There was a statistically significant correlation between 24hours urinary calcium and total serum alkaline phosphatase (r= 0.38) but no significant correlation with sex (r =0.79), age (r=0.46) or bone paint (r =0.23).

41 (79%) 8 (15%) 3 (6%)

Control group, n = 40 Frequency (%)



40 (100%)


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