Clinical Endocrinology (1977) 6,377-385.

AN INVESTIGATION INTO GONADAL DYSFUNCTION IN PATIENTS WITH IDIOPATHIC HAEMOCHROMATOSIS W. R . BEZWODA, T . H. BOTHWELL, L. A. V A N D E R WALT,* S. KRONHEIMT A N D B. L. PIMSTONE?

MKCIron and Red Cell Metabolism Unit, Department of Medicine, University of the Witwatersrand,Johannesburg, *School of Pathology, University of the Witwatersrand and South African Institute for Medical Research, Johannesburg, and fIsotope Laboratory, Department of Medicine, University of Cape Town, Observatory, South Africa (Received I I October I 9 76;revised 2 December I 9 76; accepted 3 December I 9 76)

SUMMARY

Endocrine studies were performed on twelve patients with proven idiopathic haemochromatosis. Basal gonadotrophin levels and/or their responses t o LH releasing hormone (LHRH) were low in nine patients, all of whom showed low plasma testosterone levels and clinical evidence of hypogonadism. Those patients with normal gonadotrophin responses had higher testosterone values, suggesting that the poor testosterone secretion was primarily due to inadequate trophic stimulation. No patient showed hypothyroidism of hypothalamic-pituitary origin, while the cortisol response t o hypoglycaemia was normal in all six patients studied. GH responses were more variable and difficult to interpret, since the number of the patients studied was small and the degree of hypoglycaemia after insulin was unpredict able. While hypogonadism is extremely common in patients with long-standing idiopathic haemochromatosis (Bricaire et al., 1971), there is some controversy as t o its cause. Suggested aetiologies include functional disturbance at the hypothalamic or pituitary level (Tourniaire et al., 1974; Stocks & Powell, 1972), primary gonadal failure (Simon et al., 1972), or a combination of both (Simon et al., 1972; Walker et al., 1976). In an attempt to evaluate this problem, we have studied plasma gonadotrophin responses t o both LH releasing hormone (LHRH) and clomiphene, and the plasma testosterone basally and after human chorionic gonadotrophin (HCG) in patients with proven haemochromatotis. The results of certain other tests of anterior pituitary function are also reported. P A T I E N T S AND METHODS

Patients. Twelve patients with idiopathic haemochromatosis were studied. The diagnoses in these subjects were based on the finding of the clinical, biochemical and histological Correspondence: Professor B. L. Pimstone, Department of Medicine, University of Cape Town Medical School, Observatory 7925, Republic of South Africa.

377

10.9 16.9

1:

F

M

61

54

66

58

4

M

16.4

24.9

30.8

3

M

36

27.6

24 h iron excretion after desferrioxamine (mg)

2

M

Sex

57

~~

Age

1

~~

No.

42.5

16.5

21.5

45.5

24

56

Venesections (1)

32

232

280

10.3

84.4

88.3

64.4

50.6

178

150

17.8

% Saturation

56

Present serum iron (ccg/dl)

Clinical features

.s

Scanty body hair, with fine wrinkled facial skin and small, soft testes. Not on hormone replacement therapy. Diabetic on insulin therapy. No children.

Unremarkable appearance. Menopausal at 42 years. Noendocrine symptoms.One child.

Unremarkable appearance. Hysterectomy at 42 years for menorrhagia. Hot flushes 2 years later. Cardiac involvement. Three children.

No axillary hair and scanty pubic hair. Shaves occasionally. Small soft testes. Not on hormone replacement. Has brittle diabetes, cardiac involvement and impotence. Two children.

2 R

2

&

0

N

.h weeks. No children.

7 Sparse axillary and pubic hair, with small soft testes. Eunuchoid appearance. Not on hormone replacement. Shaves twice weekly and has sexual intercourse every 2

Normal axillary and pubic hair. Normal testes. Not on hormone replacement. Claims adequate sexual function. One child

Table 1 . Clinical features of twelve patients with idiopathic haemochromatosis

27.8

M

M

56

55

54

54

10

11

12

M

M

27.2

M

30

24.6

24.1

17.8

14.5

M

56

7

46.5

36.5

4.5

41.5

3.5

1.5

41

53

231

53

273

340

12.1

21.7

86.2

17.0

93.5

97.4

Normal axillary and pubic hair. Normal testes. Shaves daily. Not on hormone replacement therapy. Normal sexual function. One child.

Small soft testes. Widespread peripheral vascular disease. Not on hormone replacement therapy. Has brittle diabetes and impotence. No children.

Atrophic testes. Impotent prior to initiation of hormone therapy. One child. Tests performed 2 months after stopping testosterone replacement. Scanty body hair and small soft testes. Not on hormone replacement therapy. Impotent for previous 4 years. Two children.

N o signs of endocrine abnormality and normal sexual function. Three children.

Scanty body hair, with small soft testes. Not on hormone replacement. Severe brittle diabetes. Impotent. No children.

C'

CA

$ 3 e0

c,

0

2

R

3

3

3

Q

-

z2.

3

'1

.R

s

A,

s

W.R. Bezwoda et al. features which are generally recognized t o be typical of the disease (Bothwell & Finch, 1962) (Table 1). None of them had ever received iron therapy or blood transfusions and there was no evidence of excessive alcohol intake. At the time of diagnosis, pigmentation and a firm hepatomegaly were present in all subjects, the plasma transferrin saturation was greater than 85% and the desferrioxamine-induced urinary iron excretion greater than 10.9 mg/24 h (mean 2 1.9 mg/24 h). Liver biopsies revealed the presence of cirrhosis and grossly excessive haemosiderin deposits located predominantly in hepatocytes in all subjects. Diabetes mellitus was present in four of the twelve and two had been in cardiac failure. None of the subjects had evidence of grossly deranged liver function tests. Specifically, all patients showed the following: Total serum bilirubin concentration was less than 1.1 mg/dl, serum GOT and GPT levels were less than 34 u/dl (normal range 2-35 units/dl), the serum albumin concentrations were greater than 2.93 g/dl (mean 3.58 g/dl) and the prothrombin indices were greater than 90% of normal. While venesection therapy had been instituted in all patients and was continued during the period of investigation, none of the tests involving the use of releasing hormones was done on days on which therapeutic phlebotomies were performed. Laboratory tests. In all patients blood was taken for plasma LH and FSH before and 20, 40,60,90, 120 and 150 min after a bolus injection of 100 pg LHRH (Hoechst), as well as on days 1, 2, 9 and 10 after oral clomiphene citrate 50 mg t.i.d. for 10 days. In two patients (5 and 6) the LHRH provocative tests was repeated, using 500 pg as a bolus injection in order to cause greater pituitary stimulation. Eight patients had plasma testosterone levels estimated basally and after intramuscular HCG 1500 units given on alternate days for three doses. All patients had plasma sampled basally for total T4 and for T3 resin uptake. Plasma TSH was also measured before and at 20 min intervals over a 1 h period after 200 pg TRH (Hoechst) had been given by intravenous injection. Six subjects (patients 1, 2, 4, 5, 9 and 12), all of whom were nondiabetic, had a standard insulin tolerance test (0.1 u/kg soluble insulin intravenously). Blood was sampled basally at 20 min intervals over a period of 1 h for glucose, cortisol and plasma GH. Analytical methods. LH and FSH were measured by a double antibody radioimmunoassay as previously described (Pimstone et al., 1974), human LH and FSH for radioiodination and human LH and FSH antisera provided by the National Pituitary Agency, U.S.A., and the HMG-IRP, reference standard for both hormones supplied by Dr R. Bangham of the Division of Biological Standards, Medical Research Council, London. The lower levels of detection are 0.4 miu for both hormones, with an interassay variation of less than 15%. Plasma testosterone was measured by radioimmunoassay , using testosterone (Sigma) as the standard, 3H-testosterone (Amersham) and antiserum made by Dr R. Millar, Department of Chemical Pathology, University of Cape Town. The lowest level of detection is 0.5 ng/ml with an intra-assay variation of 5% or less and 40-50% cross reaction with dihydrotestosterone. Free and antibody bound 13H]testosterone was separated using charcoal. All testosterone samples were run in a single assay. TSH was measured by radioimmunoassay, using the double antibody technique as previously described (McLaren et al., 1974). Human TSH for labelling, and human TSH antiserum were obtained from the National Pituitary Agency. Human TSH reference standard 68/38 was obtained from the Division of Biological Standards, M.R.C. London. T3 resin (Trisorb, Abbott) and total T4 (Tetrasorb, Abbott) tests were performed using a commercially available kit. Blood glucose was measured by the glucose oxidase technique

Gonadal dysfunction in haemochromatosis

381

(Somogyi, 1952), plasma cortisol by a competitive protein binding assay (Fiorelli et al., 1972) and GH by double antibody radioimmunoassay using a commercial kit (Sorin CEA). Normal values (adult male unless otherwise stated). After intravenous insulin (0.1 u/kg), fasting glucose should drop below 50 mg/dl between 20 and 40 min and rebound towards normal levels at 60 min. Fasting cortisol ranges from 10 to 25 pg/dl and rises to more than 25 pg/dl or doubles after a hypoglycaemic stimulus. Fasting plasma GH is below 5 ng/ml, with an incremental rise of at least 5 ng/ml after adequate hypoglycaemia in normal or hypogonad subjects. Basal TSH levels range from 0 to 5.0 pu/ml with maximal increment of more than 5 pu/ml after intravenous TRH. Basal LH and FSH levels range respectively from 4.0 to 17.0 miu/ml (9.0 or more in over 90% of cases) and from 2.0 t o 12.5 miulml, with maximal increments after LHRH of more than 16.0 and 3.0 miu/ml. Basal LH and FSH are considerably elevated in normal menopausal females (usually over 30 miu for both hormones), and show 2 - 3 times the above response t o LHRH. After clomiphene, LH usually rises by more than 6 miu/ml, but the FSH response is variable. Normal total Plasma T4 ranges from 5.3 t o 11 pg/dl and T3 resin uptakes from 23 t o 35%. Basal plasma testosterone levels in normal males range between 3 and 14 ng/ml and the minimal incremental responses t o the dose of HCG used in this study are 1-2 ng/ml.

RESULTS Response of cortisol and GH to hypoglycaemia in six patients (Table 2) An adequate hypoglycaemic stimulus was only obtained in three patients (numbers 2 , 4 and 9), while in a further two (patients 1 and 12) there was a substantial drop in glucose Table 2. The plasma cortisol (pg/dl) and GH (ng/ml) responses to changes in blood glucose (mg/dl) induced by intravenous insulin (0.1 u/kg) in six non-diabetic patients with idiopathic haemochromatosis are shown. The patient numbers correspond t o those in Table 1. ~

Patient

~

~~

0 min

20 min

40 min

60 min ~~~

1

Blood glucose Cortisol GH

112 7.2 0.3

63 8 .o 0.5

60 8.6 2.1

86 17.1 2.8

2

Blood glucose Cortisol GH

111 8.6 0.3

53 7.4 0.3

42 9.8 3.2

74 23.4 1.4

4

Blood glucose Cortisol GH

117 17.0 0.3

46 16.3 0.3

31 24.9 0.8

32 24.8 1.4

5

Blood glucose Cortisol GH

117 2.5 0.6

98 7.4 I .4

85 11.1 0.6

17 28.3 0.6

9

Blood glucose Cortisol GH

84 10.8 0.7

51 8.8 1.2

38 10.7 1.3

51 26.6 8.4

12

Blood glucose Cortisol GH

93 24.1 0.8

56 24.6 1.6

58 99.4 6.3

63 52.4 5.9

7 8 9 10 11 12

6

1 2 3 4 5

No.

Patient

Post LHRH

3.75 4.3 2.75 2.25 2.5 3.O 0 0.5 2.5 22.0 2.3 0.7 28.4 51.0

Basal

8.25 4.7 4.75 6.5 7 .O 7 .O 4 .O 4.7 3.O 17.5 1.7 5.0 16.0 5 .O 0 8 .O 2 .o 1.o 7.5 0

0

0 0.7 0 0 0

Post clorniphene

Plasma LH (miu/ml)

4 .O 3.25 1.75 1.75 6.5 9.5 2 .o 2.5 1.o 10.2 2 .o 1.2 12.25 5 .O

Basal

2 .o 1.75 1.25 0.75 0.5 4 .O 0 1.5 0 4.3 0 0.8 9.0 2.7

Post LHRH

1.o 0 0 0.8 3 .O 1.0

1.5 0.75 1.o 0 0

Post clomiphene

Plasma FSH (miu/ml)

1.o 0.5 0.9 5.7 3.0 0.6 6.4 1.8

< 1.0 < 1.0 < 1.0 < 1.0 < 0.5

Basal

1.1

1.5 0

0

0 0

0 0

Post HCG

Plasm a testosterone (nglml)

26 28 29 26 24 23

23

6.3 7.3 6.3 6.2 8.1 8.6

6.2

8.5 7.2 5.2 7.7 2.5

(%I 27 28 26 26 20

T4 (pg/dl)

Resin

Thyroid function T3 Total

~~

3.0

3.5 3.5 2.0 4.0 > 100.0

Basal

6.0

5.5 6.5 10.0 10.0

TRH

Post

Plasma TSH (wlml)

Table 3. Basal plasma LH and FSH levels are shown together with maximal increments atter 100 c(g intravenous LHRH and 50 mg clomiphene citrate t.d.s. for 10 days. Basal plasma testosterone levels are also shown, as well as peak increase responses to intramuscular HCG, when this was tested. Two patients (5 and 6) received a second LHRH injection (500 pg intravenously) some months after the first test. Basal thyroid function results are shown in all patients and the basal level and maximal increment of TSH response to 200 pg intravenous TRH in five subjects. The patient numbers correspond to those in Table 1.

.a -

2

2

4.r

l .k

f

Gonadal dysfunction in haemochromatosis

383

although not to below 50 mg/dl. The drop in glucose levels was slight and delayed in one subject (patient 5). Nevertheless in all patients but one (patient 4) a marked increase in plasma cortisol occurred, suggesting an intact pituitary ACTH reserve. Three subjects (patients 1, 4 and 5) had subnormal GH responses to hypoglycaemia but in two of these (patients 1 and 5) the hypoglycaemic stimulus was probably inadequate. Patient 4 showed a substantial hypoglycaemic response to insulin but nevertheless exhibited a poor GH elevation, which probably represented a true impairment of pituitary GH reserve. Thyroid function (Table 3). Total T4 and T3 resin uptakes were normal in all but one subject (patient 5), who showed a substantial lowering of both measurements with grossly elevated basal TSH, which suggested coincidental primary hypothyroidism. All the other patients tested showed normal basal TSH and an adequate increment after TRH. Thus no evidence of thyroid dysfunction on a hypothalamic-pituitary basis was found in any of our cases. Gonadotrophin levels and gonadal function (Table 3). Basal LH levels were below 9 miu/ml (the lowest level found in over 90% of a large series of normals studied by us) in all except patients 8 and 11. With the exception of patient 12, no subject with a low or low normal basal LH level showed a substantial rise after intravenous LHRH or oral clomiphene. Patients 5 and 6 exhibited trivial LH responses even when large (500 pg) doses of LHRH were administered. Patients 8 and 11, who had normal basal gonadotrophin levels, had LH responses t o both LHRH and clomiphene in our normal range. Patient 12, who had low basal plasma LH levels, showed a normal rise after LHRH. Fasting plasma FSH levels were more often in the normal range, since the normal scatter is wider, but those with the highest values (patients 8 and 11) responded normally t o LHRH and one of them (patient 11) was the only subject to show an FSH rise after clomiphene. In all patients who showed subnormal gonadotrophin levels or low responses to provocation, basal testosterone levels were extremely low and, in those tested, failed to respond to HCG. The two subjects (patients 8 and 11) who showed LH responsiveness t o LHRH had normal basal testosterone levels. One of these (patients 8), who was given HCG, showed a further increase in testosterone, indicating that some testicular reserve was present. DISCUSSION There was little evidence of generalized pituitary dysfunction in most of our patients. Although most of our control data (except where indicated in the case of menopausal females) was obtained in a slightly younger population group, there is no good evidence that thyroid, adrenal, male gonadal and pituitary-growth hormone function is different in the age group we have studied (range 30-66 years). All six nondiabetic patients tested showed normal cortisol responses t o hypoglycaemia, while plasma GH rose in two out of three subjects after an adequate hypoglycaemic stimulus. The third patient probably had a genuine deficiency of pituitary GH reserve. The poor hypoglycaemic responses to insulin noted in the other three patients might have been related to the presence of a prediabetic state although this was not tested by glucose tolerance. In one of these, plasma GH nevertheless rose. The lack of substantial hypoglycaemic stimuli and the small sample number unfortunately preclude the true assessment of GH deficiency in this study. However, it appeared less common than hypogonadism, a point that has also been noted by Stocks Lk Powell (1972). Evidence of thyroid dysfunction was most uncommon, being present in only one of twelve patients. Provocative tests of TSH reserve were normal in all patients tested.

384

W.R . Bezwoda et al.

In the single patient with low total T4 and a low T3 resin uptake, basal TSH was elevated, suggesting a coincidental primary (thyroid) hypothyroidism. Evaluation of the pituitary gonadal status in our patients revealed that the majority showed subnormal basal gonadotrophin levels and poor response to both clomiphene and LHRH. In addition, two subjects showed poor gonadotrophin responses t o large (500 pg) doses of LHRH, which suggests that the dysfunction might be at the level of the pituitary rather than the hypothalamus as most patients with hypogonadotrophic hypogonadism secondary t o hypothalamic dysfunction show a significant response to a large provocative dose of LHRH. In contrast, the usual dose (100 pg) cannot distinguish between the two disturbances (Mortimer et ul., 1973). The point could have been better substantiated if repetitive LHRH injections had been given over a prolonged period, since this raises LH levels more predictably in hypothalamic disease (Mortimer et al., 1974). However, it was not possible to carry out such tests for technical reasons and limited availability of LHRH. The two subjects who had normal basal LH and FSH levels and who were responsive to LHRH, had normal basal plasma testosterone levels and the one patient tested further showed some response t o HCG stimulation. One patient with a low basal LH level had a good response t o LHRH and showed low but easily measurable basal testosterone levels which responded to HCG. On the other hand, patients with poor pituitary gonadotrophin release not only had very low basal testosterone values but also showed no response to HCG when tested. While these findings are compatible with the presence of independent testicular involvement, they might alternatively suggest that poor endogenous gonadotrophin stimulation had led to a degree of testicular hypofunction that was not overcome by the short course of HCG. It was of interest to note that no patient showed an isolated primary gonadal effect, with low testosterone levels and high basal gonadotrophin values, as has been described by Simon et al. (1972), or with normal LH as reported by Walker et ul. (1976). However, the latter group measured urinary LH and did not do provocative testing after LHRH. Of the three patients who showed a normal LH response t o LHRH (patients 8, 11 and 12), two (patients 8 and 12) were clinically normal, while patient 11 was impotent and showed some degree of testicular atrophy. However, interpretation of the findings in this patient is complicated by the fact that he also had vascular disease involving the aortic bifurcation and had previously undergone a lumbar sympathectomy. In all other patients, clinical hypogonadism was associated with a disturbance of hypothalamic-pituitary gonadal reserve. Our findings indicate that the majority of patients with idiopathic haemochromatosis are clinically hypogonad and that this is due to a deficiency of gonadotrophin release closely associated with poor testicular function. In a minority of subjects (three out of twelve) in whom either basal or provoked gonadotrophin release was regarded as normal, plasma testosterone levels were also normal or showed some response to HCG (patient 12). Thus testicular involvement in idiopathic haemochromatosis appears t o be associated with gonadotrophic impairment and may well occur as a consequence of long-standing failure t o secrete the trophic hormone. In support of this suggestion are reports that long-term treatment with chorionic gonadotrophin apparently elevates plasma testosterone (Gilbert-Dreyfus, 1969) or oestrogens (Stocks & Martin, 1968) in the majority of hypogonadal patients with haemochromatosis. In addition, the fact that iron deposits are prominent in the pituitary (McDonald & Mallory, 1960) but scanty in the testes (Gilbert-Dreyfus, 1969) is also consistent with our interpretation of the present findings.

Gonadal dysfunction in haemochromatosis

385

Unlike Simon et al. (1972) we have not found elevated GH levels in the few patients that we studied. This could well be due to differences in hepatic function in the two series, since our patients did not show gross hepatic dysfunction, which is known to elevate GH (Hernandez el al., 1968). ACKNOWLEDGMENTS

Synthetic LHRH and TRH were kindly provided by Dr C. Venter, Hoechst Pharmaceuticals. The authors are also grateful t o Dr R. Millar, Department of Chemical Pathology, University of Cape Town, for performing the testosterone assays. Financial support for this study was obtained from the South African Medical Research Council and Atomic Energy Board. REFERENCES BOTHWELL, T.H. & FINCH, C.A. (1962) Iron Metabolism. Little, Brown & Co., Boston. BRICAIRE, H., LUTON, J.P., MODIGLIANI, E. & WALCKE, J.C. (1971) Syndromes endocriniens des hhochromatoses. Annales de Mkdecine Interne (Paris), 122,1225-1234. FIORELLI, G., PIOLANTI, P., FORTI, G. & FERIO, M. (1972) Determination of plasma corticosteroids and urinary cortisol by a competitive protein binding method using dextran coated charcoal. Clinica Chimica Acta, 31, 179-187. GILBERT-DREY FUS, M. (1969) La fonction testiculaire dam I’hemochromatoses idiopathique. Revue Frangaise d Endocrinologie Clinique, Nutrition et Mdtabolisme, 10,191 -203. HERNANDEZ, A., ZORILLA, E. & GERSHBERG, H. (1968) Decreased insulin production, elevated growth hormone levels, and glucose intolerance in liver disease. Diabetes, 17,327. McDONALD, R.A. & MALLORY, G.K. (1960) Hemochromatosis and hemosiderosis: study of 21 1 autopsied cases. Archives of InternalMedicine, 105,686-700. McLAREN, E.H., HENDRICKS, S. & PIMSTONE, B.L. (1974) Thyrotrophin responses to intravenous thyrotrophin-releasing hormone in patients with hypothalamic and pituitary disease. clinical Endocrinology, 3, 113-122. MORTIMER, C.H., BESSER, G.M., McNEILLY, AS., MARSHALL, J.C., HARSOULIS, P., TUNBRIDGE, W.M.G., GOMEZ-PAN, A. & HALL, R. (1973) Luteinizing hormone and follicle stimulating hormone-releasing hormone test in patients with hypothalamic-pituitary-gonadal dysfunction. British Medical Journal, iv, 73-77. MORTIMER, C.H., McNEILLY, AS., FISHER, R.A., MURRAY, M.A.F. & BESSER, G.M. (1974) Gonadotrophin-releasing hormone therapy in hypogonadal males with hypothalamic or pituitary dysfunction. British Medical Journal, iv, 617-621. PIMSTONE, B.L., BECKER, D.J. & KRONHEIM, S. (1974) FSH and LH responses to LH releasing hormone in normal and malnourished infants. Hormone and Metabolic Research, Supplement Series No. 5 , Radioimrnunoassay: Methodology and Applications in Physiology and in Clinical Studies, 179 - 184. SIMON, M., FRANCHIMONT, P., PURIE, N., FERRAND, B., VAN CAUWENBERGE, H. & BOUREL, M. (1972) Study of somatotropic and gonadotropic pituitary function in idiopathic hemochromatosis (31 cases). European Journal of Clinical Investigation, 2,384-389. SOMOGYI, M. (1952) Notes on sugar determination. Journal of Biological Chemistry, 195,19-23. STOCKS, A.E., MARTIN, F.I.R. (1968) Pituitary function in haemochromatosis. American Journal of Medicine, 45,839-845. STOCKS, A.E. & POWELL, L.W. (1972) Pituitary function in idiopathic haemochromatosis and cirrhosis of the liver. Lancet, ii, 298-300. TOURNIAIRE, J., FEVRE, M., MAZENOD, B. & PONSIN, G. (1974) Effects of clomiphene citrate and synthetic LHRH on serum luteinizing hormone (LH) in men with idiopathic hemochromatosis. Journal of Clinical Endocrinology and Metabolism, 39, 1122-1 124. WALKER, R.J., NEWTON, J.R. & WILLIAMS, R. (1976) Testicular function and the pituitary-hypothalamic axis in the hypogonadism of primary idiopathic haemochromatosis. MPdecine er Chirurgie Digestives (Paris)# 5,67-71.

An investigation into gonadal dysfunction in patients with idiopathic haemochromatosis.

Clinical Endocrinology (1977) 6,377-385. AN INVESTIGATION INTO GONADAL DYSFUNCTION IN PATIENTS WITH IDIOPATHIC HAEMOCHROMATOSIS W. R . BEZWODA, T . H...
516KB Sizes 0 Downloads 0 Views