Gestational diabetes mellitus and subsequent development of overt diabetes mellitus

GDM develops in 1-3% of all pregnancies. Women with GDM are characterized by a relatively diminished insulin secretion coupled with a pregnancy-induced insulin resistance primary located in skeletal muscle tissue. The cellular background for this insulin resistance is not known. The binding of insulin to its receptor and the subsequent activation of the insulin receptor tyrosine kinase have significant importance for the cellular effect of insulin. Thus, the pathogenesis to the insulin resistance was studied by investigating insulin receptor binding and tyrosine kinase activity in skeletal muscle biopsies from women with GDM and pregnant controls. No major abnormalities were found in GDM wherefore it is likely that the insulin resistance is caused by intracellular defects distal to the activation of the tyrosine kinase. Glucose tolerance returns to normal postpartum in the majority of women with GDM. However, previous studies, in populations quite different from a Danish population, have shown that women with previous GDM have a high risk of developing overt diabetes mellitus later in life. Hence, we aimed to investigate the prognosis of women with previous GDM with respect to subsequent development of diabetes and also to identify predictive factors for the development of overt diabets in these women. A follow-up study of diet treated GDM women diagnosed during 1978 to 1985 at the Rigshospital, Copenhagen was performed. Glucose tolerance was evaluated in 241 women (81% of the GDM population) 2-11 years after pregnancy. Abnormal glucose tolerance was found in 34.4% of the women (3.7% IDDM, 13.7% NIDDM, 17% IGT) in contrast to a control group where none had diabetes and 5.3% had IGT. Logistic regression analysis identified the following independent risk factors for later development of diabetes: a high fasting glucose level at diagnosis of GDM, a delivery more than 3 weeks before term, and an abnormal OGTT 2 months postpartum. Low insulin secretion at diagnosis of GDM was also an independent risk factor. The presence of ICA and GAD-autoantibodies in pregnancy was associated with later development of IDDM. In another study the following techniques: hyperinsulinaemic euglycaemic clamp, indirect calorimetry and tritiated glucose infusion were used to evaluate insulin sensitivity in glucose tolerant nonobese women with previous GDM and controls. A decreased insulin sensitivity due to a decreased non-oxidative glucose metabolism in skeletal muscle was found in women with previous GDM. Hence, the activity of three key enzymes in intracellular glucose metabolism (GS, HK and PFK) was studied in skeletal muscle biopsies obtained in the basal state and after 3 h hyperinsulinaemia, with the aim to identify the cellular defects causing the decreased insulin sensitivity. However, no abnormalities in enzyme activity was found. The same group of previous GDM women had a relatively reduced insulin secretion evaluated by the IVGTT. A longitudinal study of 91 GDM women showed a relatively reduced insulin secretion to oral glucose in pregnancy, postpartum as well as 5-11 years later. Thus the present review has shown that even nonobese glucose tolerant women with previous GDM are characterized by the metabolic profile of NIDDM i.e. insulin resistance and impaired insulin secretion. Hence, the combination of this finding together with the significantly increased risk for development of diabetes indicates that all women with previous GDM should have a regular assessment of their glucose tolerance in the years after pregnancy. The first OGTT should be performed around 2 months postpartum in order to diagnose women already diabetic and to identify women with the highest risk for later development of overt diabetes. Women with previous GDM comprise a target group for future intervention trials with the aim to prevent or delay development of NIDDM and IDDM.     

Smoking and diabetes mellitus

Diabetic patients die mostly from chronic vascular complications, in particular ischaemic heart disease (specially type II diabetics) and renal failure associated with diabetic nephropathy (in particular type I diabetics). Smoking--one of the basic risk factors of atherosclerosis and its complications--accelerates in diabetics the atherosclerotic process and enhances the risk of cardiovascular complications. Smoking causes endothelial dysfunction, as well as deterioration of diabetic nephropathy and retinopathy. Smoking accelerates by various mechanisms the coagulation process and causes thus deterioration of the hypercoagulation state in diabetics. Anti-smoking intervention should be along with a diabetic diet the basic step in non-pharmacological treatment of diabetics.     

Zinc and diabetes mellitus

In patients with type 1 and 2 diabetes was frequently found: low blood zinc levels, high zincuria, severe and ubiquitous cellular depletion of zinc, increased basal and after loading blood mineral clearance, and hyperglycaemia due to the reduction of pancreatic insulin secretion and to the reduced biological action of the hormone on liver, as a consequence of chronic zinc deficit. Strong endocellular zinc depletion in diabetics; low insulin secretion; insulin biological action decrease for zinc deficit; IG-I concentration decrease, that happens in this condition; insulin and IGF-I resistance; insulin and IGF-I receptors depletion in diabetics: are strong arguments for zinc pharmacological supplementation, in gastric protective formulation, to avoid gastroenteric problems.     

Juvenile diabetes mellitus

Each year members of a different medical faculty prepare articles for "Practical Therapeutics." This is the seventh in a series from the University of Texas Medical School at Houston.     

Vitiligo and juvenile diabetes mellitus

Five juvenile diabetics had vitiligo. In two children, the vitiligo preceded the onset of diabetes. Four of the five patients had thyroid, adrenal, or gastric antibodies or a combination of these. In three children HLA-B8 antigens were detected, and one additional patient had HLA-Bw15. Of eight nondiabetic children with vitiligo, one had abnormal glucose tolerance. To the evidence supporting an autoimmune form of diabetes mellitus we add another observation: the association of insulin-dependent diabetes and childhood vitiligo.     

A diabetes mellitus school

This article continues our series looking at the most common sexually transmitted infections. The risk factors, incidence and treatment of genital warts are explained and the care of the patient is described. A case study completes the overview.     

The diabetes mellitus regimen

Some patients with essential hypertension manifest increased urinary albumin excretion (UAE). Hypertensive patients with microalbuminuria manifest abnormal circadian variation of blood pressure, increased serum levels of LDL-cholesterol and lipoprotein(a), a greater rise of serum insulin in response to an oral glucose tolerance test, and greater thickness of the carotid artery than patients without microalbuminuria. A 7 year follow-up of 141 hypertensive patients, 54 with microalbuminuria and 87 without microalbuminuria, we observed 12 cardiovascular events in patients with microalbuminuria and only 2 events in the patients with normal urine albumin excretion (P < 0.0002). Creatinine clearance decreased more in patients with microalbuminuria than in those with normal UAE. In conclusion, hypertensive individuals with microalbuminuria manifest a greater incidence of cardiovascular events and more decline in renal function than patients with normal UAE. We propose that measurements of UAE may be a useful marker for cardiovascular risk in patients with essential hypertension.     

Uroradiology of diabetes mellitus

Diabetes mellitus is a prevalent disorder, well controlled in many persons with prolongation of life. Several radiologic manifestations are sufficiently specific to suggest a diagnosis in the unidentified patient, but even more important is an awareness of the sometimes life-threatening complications of diabetes which can be diagnosed from uroradiologic studies. We review the following urinary tract manifestations and complications of diabetes: pyelonephritis, perinephric abscess, renal papillary necrosis, emphysematous pyelonephritis, emphysematous cystitis, fungus infections, calcification of the vas deferens, seminal vesicle, and intrarenal branches of the renal artery, neuropathic bladder, and renal failure.