Brendan T. Kinsley

Maternal Glycemic Control and Hypoglycemia in Type 1 Diabetic Pregnancy: A randomized trial of insulin aspart versus human insulin in 322 pregnant women

OBJECTIVE—To assess the safety and efficacy of insulin aspart (IAsp) versus regular human insulin (HI) in basal-bolus therapy with NPH insulin in pregnant women with type 1 diabetes. RESEARCH DESIGN AND METHODS—Subjects (n = 322) who were pregnant or planning pregnancy were randomized to IAsp or HI as meal-time insulin in an open-label, parallel-group, multicenter study. Subjects had A1C ≤8% at confirmation of pregnancy. Insulin doses were titrated toward predefined glucose targets and A1C <6.5%. Outcomes assessed included risk of major maternal hypoglycemia, A1C, plasma glucose profiles, and maternal safety outcomes. RESULTS—Major hypoglycemia occurred at a rate of 1.4 vs. 2.1 episodes/year exposure with IAsp and HI, respectively (relative risk 0.720 [95% CI 0.36–1.46]). Risk of major/major nocturnal hypoglycemia was 52% (RR 0.48 [0.20–1.143]; P = NS) lower with IAsp compared with HI. A1C was comparable with human insulin in second (IAsp-HI −0.04 [−0.18 to 0.11]) and third (−0.08 [−0.23 to 0.06]) trimesters. A total of 80% of subjects achieved an A1C ≤6.5%. At the end of first and third trimesters, average postprandial plasma glucose increments were significantly lower with IAsp than HI (P = 0.003 and P = 0.044, respectively), as were mean plasma glucose levels 90 min after breakfast (P = 0.044 and P = 0.001, respectively). Maternal safety profiles and pregnancy outcomes were similar between treatments. CONCLUSIONS—IAsp is at least as safe and effective as HI when used in basal-bolus therapy with NPH insulin in pregnant women with type 1 diabetes and may potentially offer some benefits in terms of postprandial glucose control and preventing severe hypoglycemia.

Reduced hypothalamic-pituitary and sympathoadrenal responses to hypoglycemia in women with fibromyalgia syndrome ☆

PURPOSE To perform a detailed comparison of the hypothalamic-pituitary-adrenal axis and the sympathoadrenal system in women with and without fibromyalgia. SUBJECTS AND METHODS Fifteen premenopausal women who met the 1990 American College of Rheumatology criteria for the diagnosis of fibromyalgia and 13 healthy, premenopausal women were enrolled. We measured baseline 24-hour urinary free cortisol levels and evening and morning adrenocorticotropic hormone (ACTH) and cortisol levels, performed stepped hypoglycemic hyperinsulinemic clamp studies in which serum glucose levels were decreased from 5.0 to 2.2 mmol/L, and compared the effects of infusions of placebo and ACTH. RESULTS Women with fibromyalgia had normal 24-hour urinary free cortisol levels and normal diurnal patterns of ACTH and cortisol. There was a significant, approximately 30%, reduction in the ACTH and epinephrine responses to hypoglycemia in women with fibromyalgia compared with controls. Prolactin, norepinephrine, cortisol, and dehydroepiandrosterone responses to hypoglycemia were similar in the two study groups. In subjects with fibromyalgia, the epinephrine response to hypoglycemia correlated (P = 0.01) inversely with overall health status as measured by the fibromyalgia impact questionnaire. Graded ACTH infusion revealed similar increases in cortisol in women with fibromyalgia and healthy controls. CONCLUSIONS Patients with fibromyalgia have an impaired ability to activate the hypothalamic-pituitary portion of the hypothalamic-pituitary-adrenal axis as well as the sympathoadrenal system, leading to reduced ACTH and epinephrine responses to hypoglycemia.

Morbidity and Mortality in the Wolfram Syndrome

OBJECTIVE To determine the major causes of morbidity and mortality in the autosomal recessive Wolfram syndrome, which is defined by diabetes and bilateral progressive optic atrophy with onset in childhood or adolescence. RESEARCH DESIGN AND METHODS We abstracted and reviewed the medical records of 68 confirmed cases of Wolfram syndrome identified through a nationwide survey of endocrinologists, ophthalmologists, institutes, and homes for the blind. We also reviewed all available autopsy records. RESULTS The most common causes of morbidity and mortality were the neurological manifestations of this syndrome and the complications of urinary tract atony. There was a lower frequency of diabetic ketoacidosis, no histologically proven diabetic glomerulosclerosis, and less severe, more slowly progressive, diabetic retinopathy than in classic type I diabetic patients. Mortality in Wolfram syndrome is much higher than in type I diabetes; 60% of Wolfram syndrome patients die by age 35. Recognition of these clinical differences from classic type I diabetes is important for the proper management of Wolfram syndrome patients. CONCLUSIONS Identification of Wolfram syndrome patients among all diabetic patients presenting in childhood or adolescence is important because the management of patients with this syndrome is different from that of patients with classic type I diabetes.

Effect of Glycemic Control on Glucose Counterregulation During Hypoglycemia in NIDDM

OBJECTIVE We examined the effect of glycemic control of NIDDM on counterregulatory hormone responses to hypoglycemia and compared the effect with that seen in patients with IDDM. RESEARCH DESIGN AND METHODS Eleven subjects with NIDDM and eight age- and weight-matched control subjects and ten subjects with IDDM and ten age- and weight-matched control subjects were studied. All subjects underwent a stepped hypoglycemic-hyper-insulinemic clamp study during which plasma glucose levels were lowered in a stepwise manner from 5.0 to 2.2 mmol/l in steps of 0.6 mmol/l every 30 min. Counterregulatory hormones (epinephrine, norepinephrine, glucagon, ACTH, cortisol, and growth hormone [GH]) were measured, and a symptom survey was administered during the last 10 min of each 30-min interval. RESULTS The threshold for release of epinephrine, norepinephrine, ACTH, and cortisol occurred at higher plasma glucose levels in NIDDM than in IDDM patients (P < 0.05–0.01). The glucose threshold for release of epinephrine and norepinephrine correlated with glycemic control as measured by glycosylated hemoglobin (P < 0.05–0.01). However, for a given level of glycemic control, the threshold for release of epinephrine and norepinephrine occurred at a higher glucose level in NIDDM versus IDDM patients (P < 0.05–0.01). At the nadir level of hypoglycemia, glucagon, ACTH, and cortisol levels were all higher in NIDDM compared with IDDM subjects, whereas GH levels were lower. CONCLUSIONS Glycemic control alters counterregulatory responses to hypoglycemia in NIDDM as has been previously reported in IDDM. However, at similar levels of glycemic control, NIDDM patients release counterregulatory hormones at a higher plasma glucose level than patients with IDDM. In addition, subjects with NIDDM maintain their glucagon response to hypoglycemia. These data suggest that patients with NIDDM may be at reduced risk of severe hypoglycemia when compared with a group of IDDM patients in similar glycemic control, thus providing a more favorable risk-benefit ratio for intensive diabetes therapy in NIDDM.

The perception of safe driving ability during hypoglycemia in patients with type 1 diabetes mellitus

PURPOSE Insulin-induced hypoglycemia and its sequelae of cognitive impairment may place patients with type 1 diabetes at risk when driving and when making decisions about driving. Little is known about the factors that influence judgments of safe driving ability during hypoglycemia in these patients. PATIENTS AND METHODS Thirty men and 30 women with uncomplicated type 1 diabetes (age [mean +/- SD] 33 +/- 9 years, duration 9 +/- 3 years, hemoglobin A1c level 8.7% +/- 1.0%) underwent a stepped hypoglycemic insulin clamp. Serum glucose levels were reduced from 120 mg/dL to 80, 70, 60, 50, and then 40 mg/dL during 190 minutes. At each glucose plateau, patients completed a symptom questionnaire and neuropsychological test, estimated their glucose level, and reported whether they could drive safely. RESULTS The proportion of patients judging that they could drive safely decreased as serum glucose levels decreased from 70% at 120 mg/dL to 22% at 40 mg/dL. Men and middle-aged patients were more likely to consider it safe to drive during hypoglycemia than women and those under 25 years of age. Those who were symptomatic and those who recognized hypoglycemia were less likely to report safe driving ability during hypoglycemia. Most patients who were cognitively impaired appeared to recognize this and reported that they could not drive safely at a serum glucose level of 40 mg/dL. CONCLUSIONS Adults with type 1 diabetes need educational reinforcement of safe driving habits, particularly to check glucose levels before driving. Glucose levels less than 70 mg/dL should be treated before driving. This information is as important for middle-aged, experienced drivers as it is for younger, inexperienced drivers.

Differential Regulation of Counterregulatory Hormone Secretion and Symptoms During Hypoglycemia in IDDM: Effect of glycemic control

OBJECTIVE To determine 1) if there was a differential effect of glycemic control on individual counterregulatory hormone responses to hypoglycemia in patients with insulin-dependent diabetes mellitus (IDDM), 2) whether these modifications affect hypoglycemic symptom perception, and 3) if there was a level of glycemic control below which counterregulatory and symptomatic responses to hypoglycemia become consistently altered. RESEARCH DESIGN AND METHODS We performed hypoglycemic clamp studies on 38 patients with IDDM and 38 healthy control subjects. Glucose was lowered from 5.0 to 2.2 mmol/1 over 3 h in decrements of 0.6 mmol/1 each 30 min. Epinephrine, cortisol, growth hormone (GH), glucagon, and symptom score were measured at each glucose plateau. RESULTS In IDDM patients, HbA1 levels were positively correlated with incremental epinephrine (r = 0.58, P < 0.001) and cortisol (r = 0.52, P < 0.01) responses, but inversely correlated with GH responses (r = –0.31, P < 0.05). The increase in symptom score correlated with the epinephrine response in the IDDM patients (r = 0.57, P < 0.001), but not in the healthy control subjects (r = –0.02, NS). In IDDM patients with HbA1 ≤7.8% (n = 7), the epinephrine, cortisol, and symptomatic responses to hypoglycemia were blunted, but GH secretion was preserved. CONCLUSIONS These data suggest that 1) there is differential regulation of counterregulatory hormone secretion that is dependent on the level of glycemic control, 2) epinephrine is an important determinant of symptom perception in IDDM patients, but not in healthy control subjects, and 3) multiple defects in counterregulatory hormone secretion and symptom perception are consistently observed in patients with HbA1 levels ≤7.8%.

Diabetic gastroparesis: A review

Diabetic gastroparesis (DGP) was first described by Rundles in 1945 as part of a generalized autonomic neuropathy.’ Kassander in 1954 coined the phrase “gastroparesis diabeticorum” to describe the syndrome.* Since these original descriptions much has been learned, but fundamental questions concerning the pathophysiology, diagnosis, treatment, and prognosis of the DGP syndrome remain unanswered.

Recurrent hypoglycemia does not impair the cortisol response to adrenocorticotropin infusion in healthy humans

Previous studies have shown that hypoglycemia may reduce counterregulatory responses to subsequent hypoglycemia in healthy subjects and in patients with diabetes. The effect of hypoglycemia on the hormonal response to a nonhypoglycemic stimulus is uncertain. To test the hypothesis that the cortisol response to corticotropin (ACTH) infusion is independent of antecedent hypoglycemia, 10 healthy subjects received a standard ACTH infusion (0.25 mg Cosyntropin [Organon, West Orange, NJ] intravenously over 240 minutes) at 8:00 AM on day 1 and day 3 and a hypoglycemic insulin clamp study (1 mU/kg/min) at 8:00 AM on day 2. During the hypoglycemic clamp, plasma glucose decreased from 5.0 mmol/L to 2.8 mmol/L for two periods of 120 minutes (mean glucose, 2.9 +/- 0.03 and 2.8 +/- 0.02 mmol/L, respectively) separated by a 60-minute interval of euglycemia (mean glucose, 4.7 +/- 0.01 mmol/L). Seven subjects also had paired control studies in random order during which a 330-minute euglycemic clamp (mean glucose, 5.0 +/- 0.11 mmol/L) instead of a hypoglycemic clamp was performed on day 2. Basal ACTH (4.6 +/- 0.7 v 2.6 +/- 0.4 pmol/L, P < .02) and basal cortisol (435 +/- 46 v 317 +/- 40 nmol/L, P < .02) both decreased from day 1 to day 3 following intervening hypoglycemia. In contrast, with intervening euglycemia, neither basal ACTH (5.9 +/- 1.5 v 4.5 +/- 1.0 pmol/L) nor basal cortisol (340 +/- 38 v 318 +/- 60 nmol/L) were reduced significantly on day 3 compared with day 1. Following interval hypoglycemia, the area under the curve (AUC) for the cortisol response to successive ACTH infusions was increased (4,734 +/- 428 nmol/L over 240 minutes [day 3] v 3,526 +/- 434 nmol/L over 240 minutes [day 1], P < .01). The maximum incremental cortisol response was also significantly increased (805 +/- 63 nmol/L (day 3) v 583 +/- 58 nmol/L (day 1), P < .05). In contrast, the AUC for the cortisol response to successive ACTH infusions with interval euglycemia (3,402 +/- 345 nmol/L over 240 minutes [day 3] v 3,709 +/- 391 nmol/L over 240 minutes [day 1] and the incremental cortisol response (702 +/- 62 nmol/L [day 3] v 592 +/- 85 nmol/L [day 1] were unchanged. Following exposure to intermittent hypoglycemia in healthy humans, fasting morning ACTH and cortisol levels are reduced and the incremental cortisol response to an infusion of ACTH is enhanced. The enhanced cortisol response to exogenous ACTH infusion after intervening hypoglycemia (but not intervening euglycemia) may reflect priming of the adrenal gland by endogenous ACTH produced during the hypoglycemia. These data suggest that adrenal function testing by exogenous ACTH administration is not impaired by prior exposure to hypoglycemia. Moreover, the reduced cortisol response to recurrent hypoglycemia in patients with well-controlled diabetes is not likely the result of impaired adrenal responsiveness.