Risk factors for gestational diabetes in black population.

In a long-term longitudinal study of gestational diabetes mellitus in Black women, risk factors that were identified were age, obesity, a family history of diabetes, and the presence of hypertension. Poor predictors were a history of a previous large-for-date infant, parity, and age at first pregnancy. The prevalence of smooth muscle and nuclear autoantibodies was higher in gestational diabetic subjects. Gestational diabetic subjects who required insulin for glycemic control were more obese, had a lower frequency of the Bf-F phenotype and a higher frequency of the Bf-F1 phenotype, and had a lower frequency of the type 2 allele at the polymorphic locus adjacent to the insulin gene. Restriction-fragment-length polymorphisms flanking the insulin and apolipoprotein A-I and C-III genes, although not associated with gestational diabetes mellitus, may be associated with hyperlipidemia and subsequent atherosclerosis.

Autoantibodies in black women with class A1 or class GB diabetes mellitus.

No marker except repeated fasting glucose determinations has proven useful to ascertain prospectively which women with gestational diabetes mellitus will remain euglycemic by diet modification or will require insulin therapy. We screened 183 black women with gestational diabetes mellitus to determine if the presence of islet cell, mitochondrial, nuclear, DNA, parietal cell, smooth muscle, thyroid microsomal, thyroid thyroglobulin autoantibodies, or rheumatoid factor predicted the need for insulin therapy to maintain euglycemia in women with gestational diabetes mellitus. One hundred forty-two women maintained normal fasting plasma glucose levels with dietary modifications and 41 required institution of split-dose insulin therapy. We found no significant differences in the prevalence of these autoantibodies in black women with Class GB versus Class A1 diabetes mellitus. We conclude that screening for autoantibodies in women with gestational diabetes mellitus is not useful in determining which patients will subsequently require insulin therapy during their pregnancies.

Histocompatibility antigen subtypes in black women with class A1 or class GB diabetes mellitus.

Insulin-dependent diabetes mellitus is associated with an increased frequency of certain histocompatibility antigens located on chromosome six, the most common types being B-8, B-15, DR-3, DR-4, and DR-7. We therefore theorized that screening for these subtypes may allow the identification of those women with gestational diabetes who will remain euglycemic on dietary modification (class A1) compared with those who will require insulin to achieve euglycemia (class GB). From 1982 to 1987, 228 black women with gestational diabetes were screened for the above histocompatibility antigens. As theorized, certain histocompatibility antigen subtypes were more common in women with class GB gestational diabetes mellitus; DR-2 (41.8% versus 23.7% p = 0.015), B-15 (p = 0.07), and DR-3 (p = 0.08). However, because of the low sensitivity (42%), specificity (75%), and positive predictive value (36%), this test is impractical in the clinical management of women with gestational diabetes mellitus.