What are the best options for controlling prandial glycemia?

Enhanced absorption of insulin aspart as the result of a dispersed injection strategy tested in a randomized trial in type 1 diabetic patients

OBJECTIVE

We investigated the impact of two different injection strategies on the pharmacokinetics and pharmacodynamics of insulin aspart in vivo in an open-label, two-period crossover study and verified changes in the surface-to-volume ratio ex vivo.

RESEARCH DESIGN AND METHODS

Before the clinical trial, insulin aspart was injected ex vivo into explanted human abdominal skin flaps. The surface-to-volume ratio of the subcutaneous insulin depot was assessed by microfocus computed tomography that compared 1 bolus of 18 IU with 9 dispersed boluses of 2 IU. These two injection strategies were then tested in vivo, in 12 C-peptide-negative type 1 diabetic patients in a euglycemic glucose clamp (glucose target 5.5 ± 1.1 mmol/L) for 8 h after the first insulin administration.

RESULTS

The ex vivo experiment showed a 1.8-fold higher mean surface-to-volume ratio for the dispersed injection strategy. The maximum glucose infusion rates (GIR) were similar for the two strategies (10 ± 4 vs. 9 ± 4; P = 0.5); however, times to reach maximum GIR and 50% and 10% of the maximum GIR were significantly reduced by using the 9 × 2 IU strategy (68 ± 33 vs. 127 ± 93 min; P = 0.01; 38 ± 9 vs. 49 ± 16 min; P < 0.01; 23 ± 6 vs. 30 ± 10 min; P < 0.05). For 9 × 2 IU, the area under the GIR curve was greater during the first 60 min (219 ± 89 vs. 137 ± 75; P < 0.01) and halved until maximum GIR (242 ± 183 vs. 501 ± 396; P < 0.01); however, it was similar across the whole study period (1,361 ± 469 vs. 1,565 ± 527; P = 0.08).

CONCLUSIONS

A dispersed insulin injection strategy enhanced the effect of a fast-acting insulin analog. The increased surface-to-volume ratio of the subcutaneous insulin depot can facilitate insulin absorption into the vascular system.

Drug-induced hypoglycaemia: an update

Drugs are the most frequent cause of hypoglycaemia in adults. Although hypoglycaemia is a well known adverse effect of antidiabetic agents, it may occasionally develop in the course of treatment with drugs used in everyday clinical practice, including NSAIDs, analgesics, antibacterials, antimalarials, antiarrhythmics, antidepressants and other miscellaneous agents. They induce hypoglycaemia by stimulating insulin release, reducing insulin clearance or interfering with glucose metabolism. Several drugs may also potentiate the hypoglycaemic effect of antidiabetic agents. Administration of these agents to individuals with diabetes mellitus is of most concern. Many of these drugs, and depending on clinical setting, may also induce hyperglycaemia. Drug-induced hepatotoxicity and nephrotoxicity may lead in certain circumstances to hypoglycaemia. Some drugs may also induce hypoglycaemia by causing pancreatitis. Drug-induced hypoglycaemia is usually mild but may be severe. Effective clinical management can be handled through awareness of this drug-induced adverse effect on blood glucose levels. Herein, we review pertinent clinical information on the incidence of drug-induced hypoglycaemia and discuss the underlying pathophysiological mechanisms, and prevention and management.

Experimentally induced gestational androgen excess disrupts glucoregulation in rhesus monkey dams and their female offspring

Discrete fetal androgen excess during early gestation in rhesus monkeys (Macaca mulatta) promotes endocrine antecedents of adult polycystic ovary syndrome (PCOS)-like traits in female offspring. Because developmental changes promoting such PCOS-like metabolic dysfunction remain unclear, the present study examined time-mated, gravid rhesus monkeys with female fetuses, of which nine gravid females received 15 mg of testosterone propionate (TP) subcutaneously daily from 40 to 80 days (first to second trimesters) of gestation [term, mean (range): 165 (155-175) days], whereas an additional six such females received oil vehicle injections over the same time interval. During gestation, ultrasonography quantified fetal growth measures and was used as an adjunct for fetal blood collections. At term, all fetuses were delivered by cesarean section for postnatal studies. Blood samples were collected from dams and infants for glucose, insulin, and total free fatty acid (FFA) determinations. TP injections transiently accelerated maternal weight gain in dams, very modestly increased head diameter of prenatally androgenized (PA) fetuses, and modestly increased weight gain in infancy compared with concurrent controls. Mild to moderate glucose intolerance, with increased area-under-the-curve circulating insulin values, occurred in TP-injected dams during an intravenous glucose tolerance test in the early second trimester. Moreover, reduced circulating FFA levels occurred in PA fetuses during a third trimester intravenous glucagon-tolbutamide challenge (140 days gestation), whereas excessive insulin sensitivity and increased insulin secretion relative to insulin sensitivity occurred in PA infants during an intravenous glucose-tolbutamide test at ∼1.5 mo postnatal age. Data from these studies suggest that experimentally induced fetal androgen excess may result in transient hyperglycemic episodes in the intrauterine environment that are sufficient to induce relative increases in pancreatic function in PA infants, suggesting in this nonhuman primate model that differential programming of insulin action and secretion may precede adult metabolic dysfunction.