INTRAUTERINE CONTRACEPTIVE DEVICES IN DIABETIC WOMEN

530

Several studies suggest that RF production has a or at least aggravating effect in rheumatoid arthritis.12 IgG-RF production in itself leads to immunecomplex formation by self-association of the molecules. 13 IgG-RF immune complexes in joint fluid are complementactivating, and IgM-RF increases the size and complementfixing abilities of these immune complexes. 14 Clinical studies indicate a correlation between the level of IgM-RF (as measured with the latex test) and extra-articular manifestations15 and also between IgM-RF and unremitting course of the disease.16 An effect of the widely used aspirinlike drugs on IgM-RF production has, therefore, important clinical implications. The effect of non-steroidal anti-inflammatory agents on levels of IgM-RF in vivo has not been well studied. One study,17 which used latex-agglutination titre as the measure of IgM-RF, reported a significant decrease in the IgM-RF level in rheumatoid-arthritis patients treated with non-steroidal anti-inflammatory agents, whereas other studies have found no effect.18,19 However, in all these studies most of the patients had been receiving other non-steroidal antiinflammatory agents before the trials. Also the latex titre is an insensitive measure, in that a 50% drop in the level of IgMRF is the smallest decrease detectable. A prospective trial of the effect of piroxicam (’Feldene’) administration on serum IgM-RF levels determined by radioimmunoassay is now under way. PGE2 inhibits several cellular immune responses, such as T-cell mitogen-induced proliferation, lymphokine production, and cell-mediated cytotoxicity.3 Monocytes are the main producers of PGE2 in human blood .20 The mechanisms by which non-steroidal anti-inflammatory agents inhibit and PGE2 promotes IgM-RF production are not entirely clear, but the data are consistent with the possibility that endogenously produced PGE2 exerts a tonic inhibition of a radiosensitive suppressor T cell. Blockade of PGE2 production with non-steroidal anti-inflammatory agents derepresses the suppressor cell; this results in inhibition of IgM-RF production. Our finding21 that PGE2 receptors are selectively expressed on suppressor cells supports this concept. The data are, however, consistent with other hypotheses-e.g., stimulation of radiosensitive helper T cells, or inhibition of a radiosensitive suppressor/inducer

pathogenic

cell" by PGE2.

We thank Dr R. Searles (Lovelace Medical Center, Albuquerque, New for providing blood samples of rheumatoid-arthritis patients, Ms J. Buckelew and Ms A. Grant for technical assistance, and Ms K. Aragon for typing the manuscript

Mexico)

.

This study was supported by a grant (AG 01245-03) from the National Institute on Aging. J. L C. was supported by a grant from the Belgian National Fund of Scientific Research u2. A. R was supported bv a grant from Fundacion Gran Mariscal de Avacucho and Centro Nacional de

Enfermedades Reumaticas, MSAS, Caracas, Venezuela. should be addressed

to

J. S. G.

REFERENCES 1 Vane

JR drugs

Inhibition of

CHRISTINE GOSDEN ALAN ROSS

prostaglandin synthesis as a mechanism of

Nature New Biol

1971; 231: 232-35

action for aspirin-like

JUDITH STEEL ANTHEA SPRINGBETT

MRC Clinical and Population Cytogenetics Unit, Western General Hospital and Diabetic Department, The Royal Infirmary, Edinburgh

11 of 30 (36· 6%) insulin-dependent diabetic with fitted intrauterine contraceptive devices (IUCDs) became pregnant within 1 year, whereas the pregnancy rate for non-diabetic women fitted with the same types of IUCD by the same consultant gynaecologists over a similar time period was 4 per 100 women years (4%). As soon as the high risk was recognised, devices were removed (2 from diabetic women who were pregnant and 19 from non-pregnant diabetic women), and patients were advised about other methods of contraception. The IUCDs were examined in a scanning electron microscope with X-ray microprobe analysis to measure the amount of copper eroded from the wire, the extent of the encrustation (if any) deposited on the wire, and the composition of the deposit, and the data were compared with those for 111 devices removed from non-diabetic women. 40% of the IUCDs from diabetic women had sulphur and chloride in the deposit, compared with 15·3% of IUCDs from normal women, and fewer IUCDs from diabetic women

Summary

women

2. Trang LE Prostaglandins and inflammation. Semin Arthritis Rheum 1980; 9: 153-90. 3 Goodwin JS, Webb DR Regulation of the immune response by prostaglandins. Clin

Immunol

Immunopathol 1980; 15: 106-22. M, Johnson HE, Wendelboe-Hansen P, Christiansen SE. Isolation of human T and B lymphocytes by E rosette gradient centrifugation J Immunol Method 1980;

4. Madsen

33: 323-36. 5. Gout ZN, Baruth H, Randall LO, Ashley C, Paulsrud JR. Stereoisometric relationships among antiinflammatory activity, inhibition of platelet aggregation and inhibition of prostaglandin synthetase Prostaglandins 1975, 10: 59-66 6. Carty TJ, Stevens JS, Lombardmo JG, Parry MJ, Randall MJ Piroxicam, a structurally novel antiinflammatory compound Mode of prostaglandin synthesis inhibition Prostaglandins 1980; 19: 671-82. 7 Koopman WH, Schrohenloher RE. A sensitive radioimmunoassay for quantitation of IgM rheumatoid factor Arthritis Rheum 1980, 23: 302-08. 8. Koopman WJ, Schrohenloher RE Enhanced in vitro synthesis of IgM rheumatoid factor in rheumatoid arthritis. Arthritis Rheum 1980; 23: 985-92. 9. 10.

In patients with rheumatoid arthritis the inflamed joints are major sites of IgM-RF production. 22 Levels of PGE2 are raised in sites of inflammation; 10 high levels of PGE2 may promote local IgM-RF production in vivo and therefore exacerbate the inflammatory process. Part of the beneficial effect of prostaglandin synthetase inhibitors in patients with rheumatoid arthritis may be due to a reduction of PGE2enhanced autoantibody formation.

Correspondence

INTRAUTERINE CONTRACEPTIVE DEVICES IN DIABETIC WOMEN

Hyidberg E, Lausen HH, Jansen JA. Indomethacin plasma concentrations and protein binding in man. Eur J Clin Pharmacol 1972; 4: 119-24. Robinson DR, Levine L. Prostaglandin concentrations in synovial fluid in rheumatic

diseases action of indomethacin and aspirin In- Robinson HJ, Vane JR, eds Prostaglandin synthetase inhibitors Royal Society of Medicine New York: Raven Press, 1975: 223-28 11 Thomas Y, Sosman J, Irigoyen O, et al. Functional analysis of human T cell subsets defined by monoclonal antibodies J Immunol 1980; 125: 2402-08. 12. Johnson PM, Faulk WP. Rheumatoid factor: its nature, specificity and production in rheumatoid arthritis (review). Clin Immunol Immunopathol 1976, 6: 414-30. 13. Pope RM, Teller DC, Mannik M. The molecular basis of self-association of IgG rheumatoid factor. J Immunol 1975; 115: 365-73. 14 Winchester RJ, Agnello V, Kunkel HG. Gammaglobulin complexes in synovial fluids of patients with rheumatoid arthritis Clin Exp Immunol 1970, 6: 689-706 15 Gordon DA, Stein JL, Broder I The extraarticular features of rheumatoid arthritis a systematic analysis of 127 cases Am J Med 1973, 54: 445-52. 16. Sharp JT, Calkins E, Cohen AS, Schubart AF, Calabro JJ. Observations on the clinical, chemical and serological manifestations of RA based on the course of 154 cases Medicine 1964; 43: 445-52. 17. Himes JE, Duff IF. The effect of fenoprofen calcium (Nalfon) on levels of rheumatoid factor in patients with rheumatoid arthritis J Int Med Res 1977; 5: 412-16 18. Lussier A, Myhal D, Boost G, Varady J, Segre E, Strauss W Long term study of naproxen challenged by a short term double blind crossover study with placebo in rheumatoid patients Scand J Rheumatol 1973; Suppl 2 113-18 19. Hill H, Hill A, Mowat A, et al. Multicentre double-blind crossover trial comparing naproxen and aspirin in rheumatoid arthritis Scand J Rheumatol 1973. Supp. 2:176-81 20. Bankhurst AD, Hastain E, Goodwin JS. The nature of the prostaglandin producing mononuclear cell m human peripheral blood. J Lab Clin Med 1981, 97: 179-86 21. Goodwin JS, Kaszubowski PA, Williams RC. Cyclic AMP response to prostaglandin in subpopulations of human lymphocytes J Exp Med 1979, 150: 1260-64 22. Vaughan JH, Chihara T, Moore TL, et al. Rheumatoid factor producing cells detected by direct hemolytic plaque assay. J Clin Invest 1976; 58: 933-41

531

had calcareous deposits. In’ devices from normal women, erosion and deposition seemed to occur independently, but in IUCDs from diabetic women, where there was high erosion, also large deposits, and where there was little the erosion was slight. 7 of 14 IUCDs taken from deposit, normal women who had become pregnant with an IUCD in situ had a high sulphur plus chloride deposit: none of these IUCDs had a predominantly calcareous deposit compared with 19 - 807o of the IUCDs from non-pregnant normal women. The evidence militates against the insertion of IUCDs in diabetic patients and indicates that, even in nondiabetic women, there may be small groups for whom the risk of becoming pregnant is very high.

there

were

Introduction WOMEN taking the oral combined contraceptive pill are at increased risk of cardiovascular and cerebrovascular disease,I,2 and the incidence of these disorders in diabetic women, particularly those of childbearing age, is considerably greater than in the non-diabetic population.3 Diabetic women taking the combined oral contraceptive pill may be at particularly high risk.4 An alternative method of contraception for these women is the intrauterine contraceptive device (IUCD), which has a quoted failure rate of between 2 and 4 per 100 woman years.5 Unexpectedly, our experience was very unfortunate. 11 of 30 diabetic patients became pregnant within 1 year of insertion of the device. All the devices were inserted by experienced gynaecologists whose failure rate in non-diabetic patients was about 4 per 100 woman years. Approximately half of the group was fitted with copper 7 (Cu7) devices and halfwith plastic IUCDs. 5 of the patients who became pregnant had been fitted with Cu7 devices, 5 with ’Safe-T-Coils’, and 1 with a Dalkon shield; all the devices were in situ when pregnancy was recognised. Salpingitis developed in 1 patient: 4 patients had to have the device removed because of menorrhagia. Examination of IUCDs in a scanning electron microscope fitted with an X-ray microprobe analyser gives information about the erosion of copper from copper-bearing devices and about the elements deposited on the surfaces of the IUCDs.6,7Our studies showed that in about 1 in 5 non-diabetic women considerable amounts of calcium were deposited on the IUCD, although the amounts of erosion and deposition varied widely. The calcium deposition has now been. confirmed by others. 8 IUCDs from non-diabetic women who became pregnant with coils in situ showed rather different deposits.9 We decided to examine IUCDs removed from diabetic patients to determine the composition of the deposits and the amounts of erosion which had taken place. Patients and Methods

Unfortunately, by the time we realised it would be interesting to examine IUCDs from diabetic patients with the electron microscope, most of the devices taken from pregnant patients had been destroyed, and a policy of advising other forms of contraception had been adopted. We examined 21 coils from insulin-dependent diabetic women aged 22-37 years. The duration of diabetes ranged from 4 to 27 years. 12 patients were attending the diabetic clinic at the Royal Infirmary, Edinburgh, 1 of these patients had become pregnant with a coil in situ. Colleagues from other diabetic clinics in Britain sent us 9 coils, 1 from a patient who had become pregnant with a coil in situ. We also examined 111 IUCDs removed from normal women and 14 removed from normal women who had become pregnant with IUCDs in situ. The IUCDs were collected into sterile plastic universal containers and transported to the laboratory as quickly as possible.

Each IUCD was examined under a dissecting microscope and the whole device (for inert plastic IUCDs) or the copper-wound arms of Cu7 (’Gravigard’) devices divided into 3 portions for analysis. The portion for examination of surface topography was stored in 2-507o cacodylate-buffered glutaraldehyde for 18 h, washed in cacodylate buffer, fixed in a 1% osmium tetroxide solution, dehydrated in graded acetones, and critical-point dried from liquid CO2. This portion of IUCD was mounted on an aluminium stub and coated with a 50 nm layer of gold in a Polaron sputter coater. The portion for elemental analysis was air dried, mounted by means of carbon dag on a stub, and coated with carbon in an Edwards 306 coater fitted with a Rota tilt. The remaining portion was air dried, embedded directly in araldite polymerised at 60 °C, and cut to expose the copper wire in cross-section. The faces of the blocks were trimmed with glass knives in an ultramicrotome and coated with carbon. Several representative cross-sections of each device were photographed, and cross-sectional measurements of the original area of the copper wire, erosion layer, and deposit were made from enlarged photographs by means of a Kontron MOP measuring

system. All specimens were examined in a Cambridge S180 scanning microscope fitted with a Link X-ray microanalysis system which can detect elements with atomic numbers greater than 11. The specimen height, angle, and position of the detector were held constant during X-ray microanalysis. The specimen current was 2. 0 x 10-9 A at a beam energy of 30 keV. Three measurements were made for each IUCD. When the device was cut so that the copper wire could be seen in cross-section, the erosion was irregular, giving a "motheaten" appearance without destroying the original outline of the wire. The original diameter of the copper wire was determined. We compared the estimated original cross-sectional areas of copper wires of used devices with those of unused and short-term devices and found a low coefficient of variation. It was thus possible to see how much of the copper had dissolved away (erosion layer). Secondly, we measured the layer (varying from a very thin to a thick encrustation of substances) of deposit found on many of the devices. The original cross-sectional area of the copper wire was taken as 100%; the amounts of erosion and deposit were measured (in cm2) from enlarged photographs, and these areas were expressed as percentages of the original crosssectional area. Thirdly, the composition of the deposit (if any) was given by the X-ray analysis of the whole mount: the percentages of each of the elements were calculated from the integral X-ray count for each element in the spectrum. For the latter measurements we assumed that any element present in the deposit was accessible to the X-ray probe-i.e., that all elements in the deposit were homogeneously distributed. When the deposit layer was thin or absent, the copper of the wire was more easily accessible to the X-ray _

probe. Results Table I shows the clinical data for the diabetic patients and the results of X-ray analyses; these have been simplified to show only the amounts of copper, calcium, and sulphur plus chloride in the IUCDs; other elements present in small amounts were sodium, potassium, magnesium, and these and bring the totals to 100%. phosphorus The manufacturers (Searle) state that a Cu7 with 89 mg of copper wound as wire on to a surface area of 200 mm2, will lose 40-60 µg of copper per day. Fig. 1 shows a theoretical line for copper loss at the lowest level (40 Mg/day) and the average observed copper losses from IUCDs from normal women and from diabetic patients. Although the rate of loss of copper from the IUCDs may approximate to 40 µg/day over the first 6 months in situ, the rate ofloss after 6 months is clearly much less than 40 µg/day. There was no theoretical expectation of deposit by any manufacturers ofIUCDs. The amounts of deposit found on the copper wire are shown in fig. 2. For ethical reasons further data could not be obtained in the diabetic group, and

532 TABLE I-DETAILS OF DIABETIC PATIENTS AND THEIR IUCDS

*Not known, since IUCD sent from another centre. The sum of percentages of Cu, Ca, and S + CI does not always equal 100% since P, K, Na, and Mg were also present in small quantities. Patients 1-15 had Cu7 devices, patients 16,17,19, and 21 safe-t-coils, patient 18 a Lippes loop, and patient 20 a Dalkon shield. DVT= deep-vein thrombosis

therefore, because of the small numbers of patients within each time category, the variation was too great to allow the inference of differences between diabetic patients and normal women. We questioned whether there was any dependence on time for erosion and deposit. In most devices from normal women that had been in situ for less than 6 months at least 85% of the copper was available to the X-ray probe; thus, little deposit is laid down in the first 6 months. Only 1 device of 24 had a high level of calcification. Statistical testing shows that after 6 months in situ, the distribution of copper, 50 r-

calcium, and sulphur plus chloride on IUCDs from normal women is independent of time.’° The distribution of the percentage of copper detectable in devices removed within 6 months and in those removed after 7-38 months is shown in table II: the distributions were significantly different (&khgr;2 14. 4; p<0. 01). Unfortunately, only 1 device had been in situ in a diabetic woman for less than 6 months, so there were insufficient numbers for testing the differences in that group. Cross-sectional data allowed comparison of the amount of erosion and the amount of deposit. The results for IUCDs from normal women and from diabetic patients are shown in table III. The amounts of erosion and deposition in IUCDs from normal women all seemed to be independent, whereas in IUCDs from diabetic women there was less apparent =

Fig. 1-Percentage erosion of original cross-sectional area of]rUCD in diabetic and normal Mean values

women.

calculated by grouping the data into several time categories and finding the average for each group. This average was then plotted against the mid-point of the time category. There were differing numbers of observations in the time categories and between normal and diabetic women. SEMs =’ I umts. were

Fig. 2-Mean percentage deposit for IUCDs in normal and diabetic women.

Mean values were calculated by grouping the data into time categories as for are slightly higher than for the erosion data, ranging up to ?e units.

fig. 1. SEMs

533

TABLE II-COPPER DETECTABLE BY X-RAY

MICROANALYSIS IN IUCDS

FROM NORMAL WOMEN

Amounts of copper detectable given

as

percentages of total

X-ray counts.

TABLE III-RELATION BETWEEN AMOUNT OF EROSION AND DEPOSIT FOR DEVICES REMOVED FROM DIABETIC* AND NORMAL WOMEN AFTER MORE THAN

6 MONTHS

IN SITU

*Results for devices from diabetic women are given in parentheses. t Deposit and erosion are shown as percentages of the original cross-sectional area.

Fig. 4-Spectrum and micrograph of a copper 7 device removed from a

between erosion and deposit: devices that showed an extensive erosion layer also showed considerable deposit, and a proportion (7 of 14) women showed little response of either type. After 18 months in situ at least 4% of copper wire had been eroded in all the normal women. The upper limit of erosion (approximately 45%) does not increase with time (A. Ross, C. M. Gosden, N. B. Loudon, and A. J.

independence

Springbett, unpublished) Fig. 3 and fig. 4 show spectra

and micrographs for Cu7 devices taken from a normal woman and a diabetic woman. The profiles of elements detected by X-ray microanalysis on the IUCDs of normal women show four main groups (table IV). Copper formed more than 85% of total counts in those in which there was no deposit or the major response was copper erosion. In a second group the deposit was primarily calcareous (>85% calcium). A few IUCDs from normal

diabetic

woman.

The analysis shows a deposit but with an erosion layer (E).

(D) consisting mainly of sulphur and chloride

showed a high sulphur plus chloride response These levels are mutually exclusive. The fourth group of women showed a mixed response with some copper, some calcium, less than 15% sulphur plus chloride,

women

(>15%).

occasionally magnesium.

some

sodium, phosphorus, potassium,

or

There were significant differences among the elemental analysis profiles of the 15 copper-bearing IUCDs from diabetic patients, 14 Cu7 devices removed from non-diabetic who had become pregnant with IUCDs in situ, and 111 Cu7 devices from normal women (X6= 15 - 2; p<0. 025). In each case the results for diabetic patients’ IUCDs were

women

intermediate between those of IUCDs from pregnant nondiabetic women and those from normal women. Devices from the diabetic and pregnant non-diabetic groups had more sulphur and chloride in the deposit and less calcareous deposit than those from normal women. In the normal group about 20% oflUCDs had a predominantly calcareous deposit (>85% calcium), whereas no IUCD from the pregnant group had such a deposit. 50% of the devices in the pregnant group had more than 15% sulphur plus chloride in the deposit, compared with only 15’3% of IUCDs from the normal group. We had fewer data

cross-sectional measurements than on elemental analyses because of the difficulties in cutting cross-sections. Although it is possible to do X-ray analysis on the deposit seen in the cross-sections, we rejected this method because elements such as copper or calcium were often carried between layers during sectioning. However, for those on

TABLE IV-ELEMENTS DETECTED ON IUCDS FROM PREGNANT AND

NON-PREGNANT NORMAL WOMEN AND DIABETIC PATIENTS

Fig. 3-Spectrum and micrograph of a copper 7 device removed from a

normal

woman.

analysis shows the evidence of erosion.

The

deposit (D) to consist mainly of calcium

with little

534 devices where both cross-sectional and X-ray analysis data were available, we examined the proportions of sulphur plus chloride in both calcareous and non-calcareous deposits. Copper may have been present in the form of complex salts in the deposit layer. The amount of sulphur plus chloride laid down is significantly greater (by a Wilcoxon ranking test) in the group with more than 15% sulphur and chloride than in the group with more than 85% calcium (Z 2 - 9; p<0. 002). =

Discussion The changes observed in the IUCDs from diabetic women apparently related to the duration of the diabetes, the presence or absence of complications, or to the degree of diabetic control. All the pregnancies in the diabetic women occurred during the first 15 months of use of IUCD, with almost equal frequency for copper and plastic IUCDs.Our findings do not agree with those of workers from Denmark, 10 who found only 4 pregnancies in 118 diabetic patients in the first year of use of ’Antigon’ IUCDs. However, there was a very high expulsion rate in this series, with fourteen devices being expelled in the first year. Further studies are needed to clarify the clinical risk and elucidate the different reactions of the diabetic endometrium to the presence of an IUCD. It is possible to exclude expulsion or partial expulsion in those devices where one of the two tails was cut just below the level of the cervix thus acting as a reference point. Furthermore, each of the devices was carefully examined under the were not

dissecting microscope,

and the

coatings appeared fairly

uniform contrary to those we have seen in partially expelled devices from non-diabetic women. There were no ectopic devices in these diabetic patients. Diabetic patients are more susceptible to infection than non-diabetic subjects, and this could play a part in the high failure rate. However, only 1 diabetic patient in the earlier series had a clinical problem with infection, and with the exception of this case of salpingitis there were no other problems. The difficulties of studying bacterial colonisation of IUCDs have been discussed by Sparks et aI., 1I who

showed, by studying devices removed

at

hysterectomy, that

bacteria adhere to the endometrium rather than to the device. This is the

only

method that

overcomes

the

problems

of

contamination of the IUCDs as they are removed through the ectocervix and vagina, which can never be adequately sterilised. The cytological evidence about the presence of

actinomyces-like organisms in the genital tract, their contribution to pelvic inflammatory disease, and their association with copper and plastic IUCDs is conflicting. 12-15 Although very few devices from diabetic women will be available for full microbiological investigations, we are attempting to correlate the patterns of erosion and deposition with the flora of the genital tract. The high sulphur plus chloride content of the deposit and the non-independent patterns of erosion and deposition suggest that the high risk of pregnancy in diabetic women with IUCDs may be linked in some way to a difference in the endometrial metabolism in diabetics. Diabetes may induce an increase in the activity of the ion pump of the uterus 16 or may influence oestrogenic action in receptor binding. 17 Copperbearing IUCDs increase the calcium concentration in nondiabetic endometrium by almost three times, largely by raising levels of unbound calcium.-’ This may explain the appearance of a thick calcareous deposit on some IUCDs. Some sulphydryl-dependent enzymes interfere with the normal utilisation of glucose by the human endometrium, particularly through the Embden-Meyerhof pathway;19 this may explain the raised proportion of sulphur found in

IUCDs from diabetic women. In non-diabetic women, the fibrinolytic activity of the endometrium, which may prevent adhesion and implantation of ova, is enhanced by a copper IUCD, but in diabetic women fibrinolytic activity is not

increased. 20

Pregnancies occurring with an IUCD in situ focus our attention on the mechanism of action ofIUCDs. Suggested modes of action include prevention of the nidation of the blastocyst and spermicidal actions of copper. 21,22 Our studies in pregnant, diabetic, and normal women may show patterns that occur only when there is a high risk of pregnancy. It may be argued that only the group of pregnant women is homogeneous. Certainly, the group of diabetic women may include some women for whom the risk of pregnancy is low, and the normal group may include a subpopulation for whom the risk is very high. Some women in the normal group at high risk of pregnancy might have become pregnant had they not had their devices removed because they wanted a safer method of contraception or were worried about the risks of pelvic inflammatory disease. If we assume that those with a high of sulphur plus chloride deposit were at particularly high risk then this might suggest even greater differences between the groups. Even with the limitation that with this technique a single device gives information about one time point only and that the histories of erosion and deposition can only be inferred, certain conclusions can be drawn. The results for diabetic patients demonstrated that the high sulphur plus chloride and low calcium response is not attributable to pregnancy, since only 1 of the diabetic patients with a copper IUCD was pregnant. Furthermore, erosion and deposition (if any) are linked in IUCDs from diabetic patients but not in normal women.

The importance of intrauterine contraception, particularly for countries in the Third World, might prompt investigation of whether there are certain groups of women with a higher than normal risk of becoming pregnant. Our findings suggest that the responses are long-term rather than transitory and that certain reactions occur whether the device is inert plastic or copper-bearing. The risk of pregnancy does raise the question of whether women for whom an IUCD seems a suitable method of contraception should be advised to use spermicides mid-cycle until the high-risk groups have been identified. There may also be a group of diabetic patients who are at particularly high risk of pregnancy, but we could not identify this group. Pregnancies in diabetic women should be undertaken after careful preconceptional advice because of the problems which may occur during diabetic pregnancies and the higher risk of congenital malformation in the children of diabetic mothers. We have therefore embarked on a policy of contraception suitable for all diabetic patients, which at present includes the progesterone-only pill and mechanical methods.23 Natural methods of family planning may also be suitable. Promising advances in contraception may be close, but our experience with IUCDs in diabetic women teaches us the importance of making existing methods safer. We thank colleagues in diabetic clinics who sent devices for study, Dr J. Parboosingh and Dr F. Johnstone for gynaecological and obstetric care of the diabetic patients, Dr Nancy Loudon and all the staff of the Lothian Health Board’s Edinburgh family planning clinics for continued interest and support in all our IUCD studies, Mr Andrew Ross and Miss Elizabeth Peffers for technical assistance, and Prof. H. J. Evans for help and support.

Correspondence should be addressed to C..G., MRC Clinical and Population Cytogenetics Unit, Western General Hospital, Crewe Road. Edinburgh EH4 2XU.

535

ABNORMALITIES OF ERYTHROCYTE DEFORMABILITY AND PLATELET AGGREGATION IN INSULIN-DEPENDENT DIABETICS CORRECTED BY INSULIN IN VIVO AND IN VITRO

I. JUHAN M. BUONOCORE

R. JOUVE

Ph. VAGUE P. MOULIN B. VIALETTES

J.

Haematology Laboratory, University Hospital Timone and Department of Diabetology, University Hospital Michel Lévy, Marseille, France

Summary

Erythrocyte deformability is lower than normal in uncontrolled insulin-dependent

diabetics and returns towards normal after 24 h treatment with a feedback-controlled insulin infusion. Deformability of normal erythrocytes is reduced by incubation in plasma from uncontrolled insulin-dependent diabetics but is normal in plasma from insulin-dependent diabetics controlled by 24 h insulin infusion, or in plasma from uncontrolled insulindependent diabetics with insulin added in vitro. Therefore, insulin has a direct action on erythrocyte deformability. Platelet aggregation measured in whole blood is raised in uncontrolled insulin-dependent diabetics and returns to normal after 24 h treatment with a feedback-controlled insulin infusion. Aggregation of normal platelets rises in the presence of erythrocytes from uncontrolled insulindependent diabetics, but not erythrocytes from the same patients after 24 h treatment with insulin. The effect of insulin on platelet aggregation therefore seems to be at least partly mediated by erythrocytes. The enhanced platelet aggregation seen in uncontrolled insulin-dependent diabetics can be explained either by a direct effect of erythrocyte rigidity or by an increased release of nucleotides (ADP) by the

erythrocytes. Introduction ERYTHROCYTE deformability is lower in diabetic patients than in normal subjects. 1-3 By means of a technique of filtration through a 5 µm filter, we have observed that the abnormal deformability in insulin-dependent diabetics can be rapidly reversed by correction of the hyperglycaemia with an artificial pancreas. We also found that an infusion of insulin

Vessey MP, Thorogood M, Doll R. Myocardial infarction in young women with special reference to oral contraceptive practice. Br Med J 1975; ii: 241-45. 2. Collaborative Group Study of Stroke in Young Women. JAMA 1975; 231: 718-22. 3 Keen H, Jarrett J. Complications of diabetes. London: Edward Arnold, 1975: 180-83. 4. Steel JM, Duncan LJP. Serious complications of oral contraception in insulindependent diabetics. Contraception 1978; 17: 291-95. 5 Newton JR, Illingworth R, Elias J, McEwan J. Continuous intrauterine copper contraception for 3 years. Comparison of replacement at 2 years with continuation of use. Br Med J 1977; i 197-99. 6 Gosden CM, Ross A, Loudon NB Intrauterine deposition of calcium on copperbearing intrauterine contraceptive devices. Br Med J 1977; 1 202-06. 7 Ross A, Gosden CM, Loudon NB, Foxwell M. The copper bearing IUD: biological variation in the erosion and deposition of elements and its contraceptive importance. Br J Fam Plann 1978; 4: 1-9. 8 Sheppard BL, Bonner J. Scanning and transmission electron microscopy of material adherent to IUCDs. Br J Obstet Gynaecol 1980; 87: 155-62 9 Gosden C, Ross A, McGovern A, Reid W. The state of the device and copper levels in the products of conception in women becoming pregnant with a copper-bearing IUCD in situ. J Reprod Fertil 1979, 55: 437-46. 10. Wiese J. Intrauterine contraception in diabetic women. Fertil Steril 1977; 28: 422-25. 11. Sparks RA, Purrier BGA, Watt PJ, Elstein M. Bacteriological colonisation of uterine cavity: role of failed intrauterine contraception device. Br Med J 1981; 282: 1189-91 12 Duguid HLD, Parratt D, Traynor R. Actinomyces-like organisms in cervical smears from women using intrauterine contraceptive devices. Br Med J 1980; 281: 534-57. 13 Westrom L, Bengstsson LP, Mardh P-A. The risk of pelvic inflammatory disease in

(0’ 2 U/kg/h) reduced the abnormality of the erythrocytes, even when the hyperglycaemia was maintained by a feedbackcontrolled infusion of glucose.This suggests that the lack of insulin itself, rather than the hyperglycaemia, causes the abnormal erythrocyte deformability. The platelet hyperaggregation observed in whole blood from insulin-dependent diabetics also disappeared with correction of the hyperglycaemia, and platelets from normal subjects showed hyperaggregation in the presence of erythrocytes from uncontrolled insulin-dependent diabetics. This suggests that reduced erythrocyte deformability and increased platelet aggregation are a result not of structural changes but of functional disturbances in these cells. Our aims in this study were to see whether incubation of normal erythrocytes and platelets in plasma from controlled and uncontrolled insulin-dependent diabetics could reproduce these abnormalities and to analyse the mechanism of the action of insulin in vitro. Patients and Methods Patients The group of "uncontrolled" insulin-dependent diabetics consisted of treated diabetic patients who required stabilisation of their diabetes and whose morning dose of insulin was usually given between 7 and 7.30 A.M. On the day of the test they received no insulin and remained fasting until 9 A.M., when blood samples were taken. The mean blood glucose level at that time was 13 -.93±2.28 mmol/l (±SD). Treatment with the artificial pancreas (’Biostator’) was then begun; this maintained a normal blood glucose level for 24 h by means of a feedback-controlled intravenousinfusion of insulin. Further blood samples were then taken; the patients were then considered to be controlled. Healthy control subjects were matched for age, sex, and ABO blood group with the insulindependent diabetics.

Laboratory Investigations Blood was collected in potassium ethylene diamine tetraacetic acid (EDTA K3) and erythrocytes were separated by centrifugation at 3000 g for 10 min; plasma and the buffy coat were removed, and the erythrocytes were washed twice in isotonic "tris" buffer at pH 7-4.

Plasma was separated from citrated whole blood (0’011 mol/1) by centrifugation for 10 min at 3000 g (platelet-depleted plasma, PDP) or at 100 g (platelet-rich plasma, PRP); the platelet count of PRP was adjusted to 400 x 109/1 with PDP.

1 Mann JI,

women

using intrauterine contraceptive devices

as

compared to non-users. Lancet

1976; ii: 221-24. 14.

Joint

statement

by: Family Planning

Association Medical

Advisory Panel, National

Association of Family Planning Doctors Scientific and Advisory Committee. IUDs and actinomyces-like organisms Lancet 1981; i: 321 15. Schmidt WA, Bedrossian CWM, Ah VA, Webb JA, Bastian FO Actinomycosis and intrauterine contraceptive devices. The clinicopathologic entity. Diagn Gynaecol

Obstet 1980; 2: 165-77. AJ, Krahl ME. Accumulation in vitro of Mg and K in rat uterus ion pump activity. Biochim Biophys Acta 1973; 191: 260-68. 17. Ekka E, Vanderheyden I, De Hertogh R. Oestrogen receptors and oestrogen-induced protein synthesis in the uterus of diabetic rats. Diabetologia 1981; 20: 578-82. 18. Hicks JJ, Rosado A. Molecular distribution of trace metals in the normal and in the copper treated human secretory endometrium. Int J Fertil 1976; 21: 55-60. 19. Rosado A, Hernandez O, Aznar R, Hicks JJ. Comparative glycolytic metabolism in the normal and in the copper-treated human endometrium. Contraception 1976, 13: 17-29. 20. Larsson B, Karlsson K, Liedholm P, Radberg T, Skryten A, Astedt B. Fibrinolytic activity of the endometrium in diabetic women using copper IUCDs. Contraception 1977; 15: 711-16. 21. Tatum HJ. Copper-bearing intrauterine devices. Chn Obstet Gynaecol 1974, 17: 93-119. 19. 22. White IG. The toxicity of heavy metals to mammalian spermatozoa. Aust J Exp Biol Med 1955; 33: 359-66. 23. Steel JM, Duncan LJP. Contraception for the insulin dependent diabetic. Diabetes Care 1980; 3: 557-60. 16. Lostroch