Arteriovenous difference of calcium and citric acid in hyperparathyroidism

VOL. 4 (1959)

CLINICA

ARTERIOVENOUS

DIFFERENCE

CHIMICA

393

ACTA

OF CALCIUM

AND

CITRIC

ACID

IN

HYPERPARATHYROIDISM

Striking oscillation of the serum calcium between normal and elevated levels in hyperparathyroidism is a well-known fact indicating profound dynamic differences in calcium metabolism. This may be due to the irregular elimination of the parathyroid hormone from the tumor. During metabolic examinations performed in our patients and during the studies of the renal elimination of calcium and citric acid, we studied the arteriovenous difference of calcium and citric acid levels in 9 normal individuals, in 5 patients with different disorders of calcium metabolism or with metabolic bone disease and in 6 patients with hyperparathyroidism. patients bone, biochemical, operative and histological examination

In all these confirmed the

diagnosis. In 4 cases, adenoma of the parathyroid gland was found, in I case the nodular hyperplasia of parathyroids was histologically established.

METHOD

Blood was taken before breakfast simultaneously from the arteria femoralis and vena cubitalis. The calcium level from superficial veins of the leg proved to be the same as in the vena cubitalis. For the determination of calcium we used the method of

CLARIS

AND

COLLIP’,

citric acid was determined

according

to GEY 2.

RESULTS

The results of the examination are shown in Table I. In all 9 controls, calcium was within the range of normal levels and no significant arteriovenous difference could be demonstrated. The maximal difference of 20/blies within the range of laboratory error. In a further group of 5 patients, only one significant difference (4%) was found in a patient with tetania strumipriva and low calcium level. Striking arteriovenous differences of 12-16~; were found in all cases of hyperparathyroidism, while in the patient with hyperplastic parathyroid glands, the arteriovenous difference was lower (5’,?&). These differences could not be explained by the errors of the method, because a vast clinical material (more than IOO,OOOsamples) was examined by this method and the difference of the simultaneous determinations never exceeded the range of + 0.1 mg “/. Citric acid level is always higher in venous blood and the arteriovenous difference with the maximum of 35% shows no significant deviation between the observed groups. References p. 394

VOL. 4 (1959)

301

acid mg “,b

Citric

K.1’. E.F. V.P. G.H. H.E:.

Adenoma parathyr.

of the gland

veil2

artery

15.8

0.0

5.8

12.1

_

5.4

IO.1

(2.4

3 ‘5 s .4

‘3.7

4.9

4.2

9.6

2.8

2.3

9.5

2.8 1.8 1.7

1.X 1.2 1.4

I.9

I.4

12.4

Sodular hyperplasia of the parathyr. gland

h1.F.

L.S J.N. A.B.

IO.9

9.9

E.K. F.E. L.H.

9.1 9. L 9.7

X0rIXll

V.H. O.H. L.V. Osteoporosis Osteomalacia Hyperventilatory tetania .\T IO overdosing Tetania strunlipriva

A.C. 1:. K. l,.T. n1.s. R.P.

I.

vein

In G patients

2.0

2.0

9.0 9.3 TO.2

2.1

2.4 2.7

I.4 ‘22.-

IO.7

2.7 2.j

1.8

IO.-

9.7 IL. 0.8

with hyperparathyroidism

s-rum calcium has been found. 2. In 9 normal individuals metabolism

_

a striking

and in 5 patients

or bone disease except

1.2

I.2

2 .s

2.2

2.5

I .')

arteriovenous

with other

one case of tetania

I.9

disorders

strumipriva

difference

of

of calcium

no arteriovenous

diffcrencc of serum calcium could be detected. 3. This observation-for which no satisfactory explication has yet been foundis of interest for pathophysiological studies and for the clinical praxis because the arterial calcium level seems to be-in some cases-a better indicator of metabolic disorders in hyperparathyroidism than the level in venous blood.

4. ru’o significant

arteriovenous

acid in hyperparathyroidism

difference

as compared

could be traced

in the level of citric

with the controls.

KEFERENCES

* E. I’.

CLARK

AND

2 K. F. GEY, Intev~.

J. 13. Z.

COLLIP,

J. Sol.

Vitomir$wsch.,

Chew, 25 (1953)

63 (1925) 401. ~1.

Received

September

zgth, 1958