Prevalence and predictive value of islet cell antibodies and insulin autoantibodies in women with gestational diabetes

Prevalence and features of pancreatic islet cell autoimmunity in women with gestational diabetes from different ethnic groups

OBJECTIVE

To assess the prevalence and characteristics of islet cell autoimmunity amongst women with gestational diabetes selected from South Asian and Afro-Caribbean as well as European populations.

DESIGN

Cross-sectional retrospective survey of subject cohort.

POPULATION

Three hundred and twenty-one women with a recent history of gestational diabetes (173 European, 86 South Asian and 62 Afro-Caribbean), a median (range) of 22 (1-150) months postpartum.

RESULTS

Antibodies to Glutamic acid decarboxylase were found in 13 (4%) of these women. There was no difference in the prevalence of anti-glutamic acid decarboxylase positivity between the three ethnic groups (European 4.6%, South Asian 3.5%, Afro-Caribbean 3.2%). Anti-glutamic acid decarboxylase positive women were leaner than anti-glutamic acid decarboxylase negative women (body mass index, median (upper-lower quartile) 23.9 (22.5-26.7) vs 26.6 (23.4-30.5)kg/m2, P = 0.03, P = 0.049 allowing for ethnicity). There was no difference between glutamic acid decarboxylase-positive and glutamic acid decarboxylase-negative women for age, family history of diabetes, waist/hip ratio, prevalence of insulin treatment during pregnancy, postpartum glucose status, lipid profile and indices of insulin action and beta-cell function.

CONCLUSIONS

Markers of islet cell autoimmunity are found as frequently in gestational diabetes women of South Asian and Afro-Caribbean origin, as they are in European subjects. Identification of future risk of type 1 diabetes is relevant to the planning of clinical management and intervention strategies in women with gestational diabetes of all major ethnic groups.

Thyroid peroxidase antibodies in Mexican-born healthy pregnant women, in women with type 2 or gestational diabetes mellitus, and in their offspring

OBJECTIVE

To search for differences in the frequency of thyroid peroxidase antibodies (TPO-Ab) among 150 pregnant Mexican women who were healthy, had type 2 diabetes mellitus (DM), or had gestational diabetes mellitus (GDM).

METHODS

Fifty healthy women, 50 women with type 2 DM, and 50 women with GDM were studied at delivery. In addition, 142 of their offspring were included in the study. TPO-Ab were determined by enzyme immunoassay, and total triiodothyronine, free thyroxine, and thyroid-stimulating hormone (thyrotropin) were measured by radioimmunoanalysis.

RESULTS

TPO-Ab were < or = 70 U/mL (negative) in 50% of the healthy women and in 60% and 60% of women with type 2 DM and GDM, respectively (no significant difference). TPO-Ab were 71 to 250 U/mL (slightly positive) in 40% of healthy women and in 30% and 34% of women with type 2 DM and GDM, respectively (no significant difference). TPO-Ab were > or =251 U/mL (strongly positive) in 10% of healthy women and in 10% and 6% of women with type 2 DM and GDM, respectively. One healthy woman had subclinical hypothyroidism, and the rest were euthyroid. The newborn offspring of these Mexican women were euthyroid and had similar frequencies of TPO-Ab (all had TPO-Ab <250 U/mL).

CONCLUSION

(1) The frequency of TPO-Ab > or =251 U/mL was similar in pregnant Mexican women with GDM in comparison with those who were healthy or had type 2 DM. (2) The similar high frequencies of slightly positive TPO-Ab in the three groups of pregnant women can partially be explained by the existence of an ethnic factor, the very strong family history of DM in a substantial percentage of them, and the use of a more sensitive and specific assay for detection of TPO-Ab.

Postpartum care of the woman with diabetes

The postpartum period in women with diabetes or GDM allows both the physician and mother to relax from the intensive medical and obstetric management that has permitted, in most cases, a successful and joyous outcome. The role of the physician, however, must switch to a proactive and preventive mode to formulate a reproductive health plan for women with diabetes and GDM. The plan should be individualized to address glycemic management and surveillance, nutritional management, contraception prescription, future pregnancy planning, and lifestyle changes. Essential to the development of a reproductive health plan is the active participation of the patient, who through education gains an understanding of the far-reaching effects her active participation will have on her subsequent health and possibly on that of her future children.

Impaired insulin-stimulated nonoxidative glucose metabolism in glucose-tolerant women with previous gestational diabetes

OBJECTIVE

Our purpose was to investigate insulin sensitivity and insulin secretion in women with previous gestational diabetes.

STUDY DESIGN

Twelve women with previous gestational diabetes and 11 controls were examined by oral and intravenous glucose tolerance tests and a hyperinsulinemic euglycemic clamp including indirect calorimetry. All women were lean and had normal oral glucose tolerance test results. Activities of glycogen synthase, phosphofructokinase, and hexokinase were measured in vastus lateralis muscle biopsy specimens obtained in the basal state and after insulin stimulation.

RESULTS

Women with previous gestational diabetes had a decreased glucose disposal rate (p<0.01) because of a reduced insulin-stimulated nonoxidative glucose metabolism (6.63 +/- 0.47 vs 9.04 +/- 0.57 mg/kg fat-free mass per minute, p<0.01). The muscle activities of glycogen synthase, phosphofructokinase, and hexokinase were similar in the two groups. The first-phase insulin response to the intravenous glucose tolerance test was, in absolute terms, comparable in the two groups. However, when the decreased insulin sensitivity was taken into account, women with previous gestational diabetes had a relative insulin secretion deficiency.

CONCLUSION

Women with previous gestational diabetes have a decreased insulin sensitivity and a relative impairment of insulin secretion.

Prevalence of antibodies to glutamic acid decarboxylase in women who have had gestational diabetes

OBJECTIVES

Our purpose was to determine the prevalence of autoantibodies to glutamic acid decarboxylase in women who had had gestational diabetes, including those in whom insulin-requiring or non-insulin-requiring diabetes mellitus has since developed.

STUDY DESIGN

The study group comprised 734 women with previous gestational diabetes who were consecutive attendees to a follow-up clinic. These women were tested for autoantibodies to glutamic acid decarboxylase with a radioimmunoprecipitation assay. We similarly tested 104 women in whom permanent diabetes mellitus developed after gestational diabetes, of whom 20 were using insulin and 84 were not. Those using insulin also had fasting C-peptide levels measured.

RESULTS

Thirteen of the 734 (1.8%, 95% confidence interval 0.9% to 3.0%) women with previous gestational diabetes were positive for autoantibodies to glutamic acid decarboxylase. Of the 20 women with diabetes treated with insulin, 12 had insulin deficiency confirmed by low levels of C peptide; all 12 were positive for autoantibodies to glutamic acid decarboxylase. Of the 84 women with diabetes not requiring insulin, 6 (7.1%, 95% confidence interval 2.7% to 14.9%) were positive for autoantibodies to glutamic acid decarboxylase.

CONCLUSIONS

The prevalence of autoantibodies to glutamic acid decarboxylase in women with previous gestational diabetes was 1.8%. Our data also showed that insulin-dependent diabetes mellitus will develop in 1.7% of women with gestational diabetes. A positive test for autoantibodies to glutamic acid decarboxylase may help in the early identification of insulin-dependent diabetes mellitus. Adult-onset insulin-dependent diabetes mellitus developed in only 5.2% (12/230) of women with previous gestational diabetes who later had diabetes mellitus.

Islet cell antibodies and beta-cell function in gestational diabetic women: comparison to first-degree relatives of type 1 (insulin-dependent) diabetic subjects

In order to further characterize women with islet cell antibodies (ICA) at the diagnosis of gestational diabetes (GDM), we aimed to compare titres and persistence as well as B-cell function with those of ICA+ first-degree relatives of Type 1 (insulin-dependent) diabetic subjects. Titres at detection of ICA were compared between 69 women with GDM and 53 relatives. Persistence of ICA positivity was investigated in 33 ICA+ gestational diabetic women and 39 relatives (mean follow-up: 13 months). Assessment of the acute insulin response, through an intravenous glucose tolerance test (IVGTT), was carried out in 9 ICA+ women with previous GDM and normal oral glucose tolerance, and their results were compared to those of a control group (9 women) and a group of 12 adult ICA+ relatives. In comparison with first-degree relatives, women with GDM had a higher ICA prevalence, especially with titres of < 20 JDF, and a similar persistence at follow-up. Women with ICA at diagnosis of GDM and normal oral glucose tolerance after pregnancy showed a decreased insulin response to glucose as compared to the control group. Results of the IVGTT closely paralleled those from adult ICA+ relatives. It is concluded that ICA+ gestational diabetic women share with ICA+ first-degree relatives of Type 1 diabetic subjects metabolic and immunologic disturbances.