Exp. Clin. Endocnnol. 99 (1992) 87-90
Experimental and Clinical Endocrinology © 1992 Johann Ambrosius Barth
Serum Urate and Renal Function in Different Forms of Hypercalcemia L. Lind and S. Ljunghall
Key words: Urate - Calcium - Hypercalcemia - Hyperparathyroidism
Summary: In order to investigate the relationships between serum calcium, urate and kidney function, serum calcium, urate, creatinine and urea were measured at 100 occasions in hypercalcemic cancer patients together with 113 preoperative measurements in HPT subjects and 106 measurements in normocalcemic control persons. When compared to normocalcemic control subjects (serum
urate 336 ± 110 ltmol/l) both HPT subjects (356 ± 98 mmol/ I, p < 0.006) and the cancer patients (407 ± 179 mmol/l, p < 0.001) showed raised levels of serum urate. While serum urate
This relation persisted also after correcttion for age, sex and serum creatinine in the multiple regression analysis. Serum creatinine was similar in all groups but significantly correlated to serum calcium only in the HPT subjects (r = 0.29,
p < 0.003). Serum urea was not significantly correlated to serum calcium in any of the groups but was elevated in the cancer group (8.3 ± 4.4 vs 6.2 ± 2.9 imol/l in the control group, p < 0.0001). This elevation in serum urea seen in the cancer patients might rather be explained by dehydration or catabolism than an impaired kidney function.
In conclusion, while serum urate is related to the kidney
(r = 0.40-059, p < 0.0001) a significant correlation to serum calcium was only seen in the HPT group (r = 0.28, p < 0.004).
function both in normo- and hypercalcemia, it also seems to be related to the hypercalcemia in HPT subjects but not in cancer patients. In hypercalcemia associated with malignant disorders, other factors such as an increased turnover of cyclis nucleotides and dehydration may also contribute to the hyperuricemia.
Introduction
was reversible in patients with hypercalcemia of non-
was
correlated
to
serum
creatinine
in
all
groups
HPT origin (Lins, 1979) while in HPT no effect or even a
primary hyperparathyroidism (HPT) and in hypercalcemia due to malignant disorders (Andersson and Berg-
further affliction has been reported after parathyroid surgery (Lins, 1979; Jones et al., 1983). However, the kidney function in patients with mild
dahl, 1977; Purnell et al, 1971; Zeffren and Heinemann,
HPT who were detected in a large health screening survey
1962). This deterioration in kidney function has been
was found to be normal and no deterioration in serum
attributed to calcium deposits in the renal tubules (Carone
creatinine was seen after 14 years of observation (Palmér et al., 1987). An association between hyperuricemia and primary hyperparathyroidism (HPT) has been described by several authors (Christensson, 1977; Sitges-Serra, 1981; Ljunghall and Akerström, 1982; Yoneda et al., 1983). Raised levels of serum urate have been shown to be due to a reduced renal clearence of urate in HPT (Ljunghall and Akerström, 1982) while hyperuricemia in malignancy-associated hypercalcemia might also be caused by other factors, e.g. an increased production of urate.
An impaired kidney function has been described both in
et al., 1960; Bank and Aynedjian, 1965), formation of atopic calcium-phosphate complex (David and David, 1975) or by altered renal hemodynamics (Lins, 1979; Haddy, 1960). Both a decreased glomerular filtration rate (GFR) and a
reduced renal blood flow (RBF) have been associated with hypercalcemia (Lins, 1979). These impairments in renal function were reported to be less pronounced in HPT than in hypercalcemia due to other causes (Lins, 1979). On the other hand, the disturbed renal function
Downloaded by: Universite Laval. Copyrighted material.
Department of Internal Medicine (Head: Prof. S Ljunghall), University Hospital, Uppsala/Sweden
Exp. Clin, Endocrinol. 99 (1992) 2
88
antly increased in the cancer group compared to the HPT subjects as well as the controls. This difference was also seen when the influences of age, sex and serum creatinine were taken into account in a co-variance analysis. 180
o
160
E
Material and Methods
o
o
.2- 140
o
The study was carried out on a retrospective material at the Gävle County Hospital. Altogether, 113 preoperative serum measurements from 86 patients with surgically proven HPT were used together with loo measurements from 53 patients with malignant disorders. Most common diagnoses were bronchial cancer and mammary cancer. No case of renal carcinoma
was included in the study. All serum samples included a calcium value (corrected for albumin) above 2.60 mmol/l. No more than three measurements were allowed from the same
individual and were then taken at least one week apart. To obtain reference values, serum measurements from 106 hospitalized normocalcemic patients were used, The control patients were selected in order to be age-and-sex-representative to the cancer and FIPT patients.
Table 1 Serum calcium. urate and kidney function in hypercalcemic groups and control persons
Observations Age (years) Sex (% male) Serum calcium
Control persons
HPT subjects
Cancer patients
106
113
100
67±12
64±12
66±11
42
17
62
2.42 ± 0.09 3.01 ± 0.23e 2.99 ± 0.35e
(mmolJl)
Serum creatinine (llmolIl) Serum urea
90 ± 34
87 ± 22
89 ± 29
6.2 ± 2.9
6.2 ± 2.7
8.3 ± 4,4e
336±110
356±98a
4O7±l79b
l.tmolIl)
Serum urate
C C
o
120
ca cl>
o
E
80 2 a) Cl)
6 O
40
24
2,8
2,6
3,2
3
Serum calcium, albumin, creatinine urate and urea were all analysed in the autoanalyser SMAC (Technicon Inc., USA). All data were computerized and the statistical program SAS
(SAS [nc., NC, USA) was used for analysis. The Student's unpaired t-test was used for calculating differences between groups. Pearson's correlation coefficient was given when the
3,8
Fig. 1 Relation between serum calcium and serum creatinine in patients with primary hyperparathyroidism (r = 0.29,
p
Experimental and Clinical Endocrinology © 1992 Johann Ambrosius Barth
Serum Urate and Renal Function in Different Forms of Hypercalcemia L. Lind and S. Ljunghall
Key words: Urate - Calcium - Hypercalcemia - Hyperparathyroidism
Summary: In order to investigate the relationships between serum calcium, urate and kidney function, serum calcium, urate, creatinine and urea were measured at 100 occasions in hypercalcemic cancer patients together with 113 preoperative measurements in HPT subjects and 106 measurements in normocalcemic control persons. When compared to normocalcemic control subjects (serum
urate 336 ± 110 ltmol/l) both HPT subjects (356 ± 98 mmol/ I, p < 0.006) and the cancer patients (407 ± 179 mmol/l, p < 0.001) showed raised levels of serum urate. While serum urate
This relation persisted also after correcttion for age, sex and serum creatinine in the multiple regression analysis. Serum creatinine was similar in all groups but significantly correlated to serum calcium only in the HPT subjects (r = 0.29,
p < 0.003). Serum urea was not significantly correlated to serum calcium in any of the groups but was elevated in the cancer group (8.3 ± 4.4 vs 6.2 ± 2.9 imol/l in the control group, p < 0.0001). This elevation in serum urea seen in the cancer patients might rather be explained by dehydration or catabolism than an impaired kidney function.
In conclusion, while serum urate is related to the kidney
(r = 0.40-059, p < 0.0001) a significant correlation to serum calcium was only seen in the HPT group (r = 0.28, p < 0.004).
function both in normo- and hypercalcemia, it also seems to be related to the hypercalcemia in HPT subjects but not in cancer patients. In hypercalcemia associated with malignant disorders, other factors such as an increased turnover of cyclis nucleotides and dehydration may also contribute to the hyperuricemia.
Introduction
was reversible in patients with hypercalcemia of non-
was
correlated
to
serum
creatinine
in
all
groups
HPT origin (Lins, 1979) while in HPT no effect or even a
primary hyperparathyroidism (HPT) and in hypercalcemia due to malignant disorders (Andersson and Berg-
further affliction has been reported after parathyroid surgery (Lins, 1979; Jones et al., 1983). However, the kidney function in patients with mild
dahl, 1977; Purnell et al, 1971; Zeffren and Heinemann,
HPT who were detected in a large health screening survey
1962). This deterioration in kidney function has been
was found to be normal and no deterioration in serum
attributed to calcium deposits in the renal tubules (Carone
creatinine was seen after 14 years of observation (Palmér et al., 1987). An association between hyperuricemia and primary hyperparathyroidism (HPT) has been described by several authors (Christensson, 1977; Sitges-Serra, 1981; Ljunghall and Akerström, 1982; Yoneda et al., 1983). Raised levels of serum urate have been shown to be due to a reduced renal clearence of urate in HPT (Ljunghall and Akerström, 1982) while hyperuricemia in malignancy-associated hypercalcemia might also be caused by other factors, e.g. an increased production of urate.
An impaired kidney function has been described both in
et al., 1960; Bank and Aynedjian, 1965), formation of atopic calcium-phosphate complex (David and David, 1975) or by altered renal hemodynamics (Lins, 1979; Haddy, 1960). Both a decreased glomerular filtration rate (GFR) and a
reduced renal blood flow (RBF) have been associated with hypercalcemia (Lins, 1979). These impairments in renal function were reported to be less pronounced in HPT than in hypercalcemia due to other causes (Lins, 1979). On the other hand, the disturbed renal function
Downloaded by: Universite Laval. Copyrighted material.
Department of Internal Medicine (Head: Prof. S Ljunghall), University Hospital, Uppsala/Sweden
Exp. Clin, Endocrinol. 99 (1992) 2
88
antly increased in the cancer group compared to the HPT subjects as well as the controls. This difference was also seen when the influences of age, sex and serum creatinine were taken into account in a co-variance analysis. 180
o
160
E
Material and Methods
o
o
.2- 140
o
The study was carried out on a retrospective material at the Gävle County Hospital. Altogether, 113 preoperative serum measurements from 86 patients with surgically proven HPT were used together with loo measurements from 53 patients with malignant disorders. Most common diagnoses were bronchial cancer and mammary cancer. No case of renal carcinoma
was included in the study. All serum samples included a calcium value (corrected for albumin) above 2.60 mmol/l. No more than three measurements were allowed from the same
individual and were then taken at least one week apart. To obtain reference values, serum measurements from 106 hospitalized normocalcemic patients were used, The control patients were selected in order to be age-and-sex-representative to the cancer and FIPT patients.
Table 1 Serum calcium. urate and kidney function in hypercalcemic groups and control persons
Observations Age (years) Sex (% male) Serum calcium
Control persons
HPT subjects
Cancer patients
106
113
100
67±12
64±12
66±11
42
17
62
2.42 ± 0.09 3.01 ± 0.23e 2.99 ± 0.35e
(mmolJl)
Serum creatinine (llmolIl) Serum urea
90 ± 34
87 ± 22
89 ± 29
6.2 ± 2.9
6.2 ± 2.7
8.3 ± 4,4e
336±110
356±98a
4O7±l79b
l.tmolIl)
Serum urate
C C
o
120
ca cl>
o
E
80 2 a) Cl)
6 O
40
24
2,8
2,6
3,2
3
Serum calcium, albumin, creatinine urate and urea were all analysed in the autoanalyser SMAC (Technicon Inc., USA). All data were computerized and the statistical program SAS
(SAS [nc., NC, USA) was used for analysis. The Student's unpaired t-test was used for calculating differences between groups. Pearson's correlation coefficient was given when the
3,8
Fig. 1 Relation between serum calcium and serum creatinine in patients with primary hyperparathyroidism (r = 0.29,
p
