1020 PROLACTIN SECRETION IN OBESE PATIENTS
SIR,-Kopelman et al.’ reported that prolactin responses to insulin hypoglycæmia and to TRH injection were, respectively, absent and significantly reduced in massively obese patients. In the same patients, however, there was a significant prolactin response when insulin, TRH, and gonadotropin-releasing hormone were administered together in a combined test. This report may be misleading. No comparison with normal weight subjects was shown and, moreover, the "significant" prolactin response was of the same magnitude (424% increase above baseline value) as that obtained in the TRH test, when it was significantly reduced in comparison with that of lean controls. The note of caution against the use of the combined tests seems unwarranted. Kopelman et al. postulate a hypothalamic alteration in obesity. However, a reduced prolactin response to TRH, although not incompatible with this conclusion, raises the possibility that a pituitary defect is also present in these patients. We have studied the prolactin response to insulin hypo-
glycaemia (0-1 U crystalline insulin/kg body-weight i.v.), arginine infusion (0-5 g arginine hydrochloride as 10% solution infused i.v. in 30 min, maximum 50 g), and TRH injection (200 µg i.v.) in two male and ten female subjects, aged 24-46, weighing 102.5±7.03% above ideal body-weight, and in twelve normal-weight controls. Plasma prolactin levels were determined by radioimmunoassay. An adequate blood glucose fall (under 50% of baseline value and less then 40 mg/dl) accompanied by typical symptoms of hypoglycaemia occurred after insulin injection in all subjects. Prolactin secretion was virtually absent (see table), in accord with Kopelman’s results, PROLACTIN SECRETION IN OBESE PATIENTS AND NORMAL-WEIGHT CONTROLS
RATES OF COMPLICATIONS ASSOCIATED WITH LAPAROSCOPY STERILISATION ANALYSED BY TIMING OF OPERATION IN RELATION OF TERMINATION OF PREGNANCY
I
I
I
i
number of operations surveyed in the U.K. during 1976-77, the complication-rates for the two major methods of sterilisation were not raised when the operation was accompanied by a vaginal termination of pregnancy. It is difficult to compare one series with another for the definitions of complications vary as do the populations examined. However, by internal comparison methods several studies from different parts of the world now seem to show that the physical risks of the combined operation may have been exaggerated. Many previous surveys, including the Confidential Enquiry, were not designed to examine the psychological effects of sterilisation. Cheng et al. found a group of 2-10% (depending upon how the data are analysed) who might have changed their mind about the operation. Decisions made at a time of high emotion may be regretted later and those women who would have second thoughts about sterilisation might not be identified so precisely at the time of consideration of a termination of pregnancy. It may be that this emotional reaction is the real contraindication to sterilising at the same time as terminating. Perhaps this facet, of the problem needs to be examined now that physical complications seem to be assuming lesser significance.
Queen Charlotte’s London SW3 6LT I
I
Hospital for Women,
GEOFFREY CHAMBERLAIN
I
Values in ng/2 h, as mean values±SEM of secretory areas.
in response to hypoglycæmia. It was also significantly reduced after arginine infusion. Prolactin response to TRH was not significantly different from that in controls. These results indicate a suprapituitary, probably hypothalamic alteration in the control of prolactin secretion in obesity. F. CAVAGNINI C. MARASCHINI First Medical Clinic, M. PINTO University of Milan, ,
A. DUBINI
20122 Milan, Italy
SAFETY OF POST-ABORTION STERILISATION
SIR,—Dr Cheng and colleagues (Sept. 29, p. 682) found of
no
when a laparotomy sterilisation was performed with a termination of pregnancy than for the interval operation. They refer to several studies which indicate greater risks of combined termination and sterilisation by various routes, and this has almost become accepted thinking. However, their study must be added to the growing body of data which supports the opposite point of view-that when the two procedures are done together, there need not be an increase in the incidence of complications. The table shows data from the Confidential Enquiry into Laparoscopy.2 in a large greater
1.
rate
complications
Kopelman PG, White N, Pilkington TRE, Jeffcoate SL. Impaired hypothalamic control of prolactin secretion in massive obesity. Lancet 1979; i:
747-49. 2. Chamberlain G, Brown JC, eds. Gynæcological laparoscopy: The report of the working party of the confidential enquiry into gynaecological laparoscopy. London: Royal College of Obstetricians and Gynæcologists, 1978.
CIMETIDINE AND SEBUM EXCRETION
SIR,—Solar hypotonia delayed my reply to the comments of Dr Burton and Dr Lovall (Aug. 11, p. 304) on the possible mechanism and therapeutic consequences of the inhibition of sebum excretion by cimetidine.1 The reason why I do not yet feel inclined to settle for one particular mechanism of action is our curious observations in the rat which led to the clinical studies. When the first Nature paper on H2 blockers appeared2 I wrote to Smith, Kline and French about the obvious potential uses of these drugs in dermatology and asked for some to play with; alas, our study was prevented by recognition of the toxicity of metiamide. I was already struck by the curious distribution of H blockers within the skin and in what was dismissed as "the vestigial preputial gland"3 (in fact a very active sex-attractant producing sebaceous gland 4) in the autoradiographs which had been done by S.K.F., and it was this which made me suspect a potential action on the sebaceous glands as well as the obvious actions on skin vessels. We did the studies about five years ago, mea1. Lyons F, Cook J, Shuster S. The inhibition of sebum excretion by an H2 blocker. Lancet 1979; ii: 1376. 2. Black JW, Duncan WAM, Ganellin CR, Parsons ME. Definition and antagonism of histamine H2 receptors. Nature 1972; 236: 385. 3. Cross SAM. In: International symposium on histamine H2-receptor antagonists. London: S.K.F., 1973: 35. 4. Thody AJ, Donohoe SM, Shuster S. The production of preputial gland sex attractants in the female rat by alpha-MSH. Acta Endocr 1979; suppl 225: 254.
SIR,-Kopelman et al.’ reported that prolactin responses to insulin hypoglycæmia and to TRH injection were, respectively, absent and significantly reduced in massively obese patients. In the same patients, however, there was a significant prolactin response when insulin, TRH, and gonadotropin-releasing hormone were administered together in a combined test. This report may be misleading. No comparison with normal weight subjects was shown and, moreover, the "significant" prolactin response was of the same magnitude (424% increase above baseline value) as that obtained in the TRH test, when it was significantly reduced in comparison with that of lean controls. The note of caution against the use of the combined tests seems unwarranted. Kopelman et al. postulate a hypothalamic alteration in obesity. However, a reduced prolactin response to TRH, although not incompatible with this conclusion, raises the possibility that a pituitary defect is also present in these patients. We have studied the prolactin response to insulin hypo-
glycaemia (0-1 U crystalline insulin/kg body-weight i.v.), arginine infusion (0-5 g arginine hydrochloride as 10% solution infused i.v. in 30 min, maximum 50 g), and TRH injection (200 µg i.v.) in two male and ten female subjects, aged 24-46, weighing 102.5±7.03% above ideal body-weight, and in twelve normal-weight controls. Plasma prolactin levels were determined by radioimmunoassay. An adequate blood glucose fall (under 50% of baseline value and less then 40 mg/dl) accompanied by typical symptoms of hypoglycaemia occurred after insulin injection in all subjects. Prolactin secretion was virtually absent (see table), in accord with Kopelman’s results, PROLACTIN SECRETION IN OBESE PATIENTS AND NORMAL-WEIGHT CONTROLS
RATES OF COMPLICATIONS ASSOCIATED WITH LAPAROSCOPY STERILISATION ANALYSED BY TIMING OF OPERATION IN RELATION OF TERMINATION OF PREGNANCY
I
I
I
i
number of operations surveyed in the U.K. during 1976-77, the complication-rates for the two major methods of sterilisation were not raised when the operation was accompanied by a vaginal termination of pregnancy. It is difficult to compare one series with another for the definitions of complications vary as do the populations examined. However, by internal comparison methods several studies from different parts of the world now seem to show that the physical risks of the combined operation may have been exaggerated. Many previous surveys, including the Confidential Enquiry, were not designed to examine the psychological effects of sterilisation. Cheng et al. found a group of 2-10% (depending upon how the data are analysed) who might have changed their mind about the operation. Decisions made at a time of high emotion may be regretted later and those women who would have second thoughts about sterilisation might not be identified so precisely at the time of consideration of a termination of pregnancy. It may be that this emotional reaction is the real contraindication to sterilising at the same time as terminating. Perhaps this facet, of the problem needs to be examined now that physical complications seem to be assuming lesser significance.
Queen Charlotte’s London SW3 6LT I
I
Hospital for Women,
GEOFFREY CHAMBERLAIN
I
Values in ng/2 h, as mean values±SEM of secretory areas.
in response to hypoglycæmia. It was also significantly reduced after arginine infusion. Prolactin response to TRH was not significantly different from that in controls. These results indicate a suprapituitary, probably hypothalamic alteration in the control of prolactin secretion in obesity. F. CAVAGNINI C. MARASCHINI First Medical Clinic, M. PINTO University of Milan, ,
A. DUBINI
20122 Milan, Italy
SAFETY OF POST-ABORTION STERILISATION
SIR,—Dr Cheng and colleagues (Sept. 29, p. 682) found of
no
when a laparotomy sterilisation was performed with a termination of pregnancy than for the interval operation. They refer to several studies which indicate greater risks of combined termination and sterilisation by various routes, and this has almost become accepted thinking. However, their study must be added to the growing body of data which supports the opposite point of view-that when the two procedures are done together, there need not be an increase in the incidence of complications. The table shows data from the Confidential Enquiry into Laparoscopy.2 in a large greater
1.
rate
complications
Kopelman PG, White N, Pilkington TRE, Jeffcoate SL. Impaired hypothalamic control of prolactin secretion in massive obesity. Lancet 1979; i:
747-49. 2. Chamberlain G, Brown JC, eds. Gynæcological laparoscopy: The report of the working party of the confidential enquiry into gynaecological laparoscopy. London: Royal College of Obstetricians and Gynæcologists, 1978.
CIMETIDINE AND SEBUM EXCRETION
SIR,—Solar hypotonia delayed my reply to the comments of Dr Burton and Dr Lovall (Aug. 11, p. 304) on the possible mechanism and therapeutic consequences of the inhibition of sebum excretion by cimetidine.1 The reason why I do not yet feel inclined to settle for one particular mechanism of action is our curious observations in the rat which led to the clinical studies. When the first Nature paper on H2 blockers appeared2 I wrote to Smith, Kline and French about the obvious potential uses of these drugs in dermatology and asked for some to play with; alas, our study was prevented by recognition of the toxicity of metiamide. I was already struck by the curious distribution of H blockers within the skin and in what was dismissed as "the vestigial preputial gland"3 (in fact a very active sex-attractant producing sebaceous gland 4) in the autoradiographs which had been done by S.K.F., and it was this which made me suspect a potential action on the sebaceous glands as well as the obvious actions on skin vessels. We did the studies about five years ago, mea1. Lyons F, Cook J, Shuster S. The inhibition of sebum excretion by an H2 blocker. Lancet 1979; ii: 1376. 2. Black JW, Duncan WAM, Ganellin CR, Parsons ME. Definition and antagonism of histamine H2 receptors. Nature 1972; 236: 385. 3. Cross SAM. In: International symposium on histamine H2-receptor antagonists. London: S.K.F., 1973: 35. 4. Thody AJ, Donohoe SM, Shuster S. The production of preputial gland sex attractants in the female rat by alpha-MSH. Acta Endocr 1979; suppl 225: 254.
