Clinical Briefs

By Louis Kuritzky, MD

Induction of Long-term Glycemic Control in Newly Diagnosed Type 2 Diabetic Patients is Associated with Improvement of Beta-Cell Function

Type 2 diabetes (DM2) is characterized by insulin resistance accompanied by a progressive decline in beta cell function (BCF). Sustained supranormal glucose levels appear to further impair BCF, a process labeled glucotoxicity. Insufficient insulin production also favors lipolysis, which results in lipotoxicity from accumulation of excess fatty acids. Initial data has supported the concept that early intensive glycemic control may truncate glucotoxicity, potentially preserving BCF.

In an attempt to clarify the role of early intensive glycemic control, newly diagnosed DM2 patients (n = 126) were treated with insulin by means of an insulin pump on an inpatient basis for two weeks, after which they were discharged. Subsequent to discharge patients were managed with diet only, and were monitored at 3, 6, 12, and 24 months. Ten percent of subjects, despite attempts at intensive glycemic control, failed to achieve excellent control, and were considered therapeutic failures, and dropped from followup and analysis.

Impressive numbers of patients were able to maintain near-euglycemia on diet alone at months 3 (73%), 6 (67%), 12 (47%), and 24 (42%). This persistent restoration of diet-controllable euglycemia is generally interpreted to indicate a restoration of BCF. No particular baseline characteristics (eg, pre-treatment FBS, A1C, and BMI) predicted which persons would be most likely to maintain euglycemia after intensive glucose control. Whether intervention with oral agents leads to similar restoration of BCF remains to be elucidated.

Li Y, et al. Diabetes Care. 2004;27: 2597-2602.

Predicting Bacterial Cause in Infectious Conjunctivitis

Only about half of acute conjunctivitis cases are bacteriaI. At presentation, it is often unclear whether patients are suffering acute bacterial conjunctivitis (ABC), or acute viral conjunctivitis (AVC). Since antibiotics are not of value in AVC, distinguishing the two entities is highly relevant. In the face of diagnostic uncertainty, most patients (approximately 80%) receive antibiotics.

Study subjects comprised patients (n = 184) from general practice settings in the Netherlands. Inclusion criteria required evidence of conjunctivitis and either purulent discharge or signs of lid adhesion, designated glued eyes. All subjects underwent conjunctival cultures.

A variety of clinical markers were assessed to determine predictive value for ABC, including fever, allergy history, distribution of erythema, edema, characteristics of secretions, bilaterality, itching, foreign body sensation, burning, and glued eyes. Multivariate analysis indicated that 3 determinants-history of conjunctivitis, itch, and presence of glued eyes-predicted ABC. Glued eyes was a positive predictor (5 points for both eyes, 2 points for one), whereas history of conjunctivitis (-2 points), and itch (-1 point) were negative predictors. A total score of +2 or greater, if used as the cutoff for initiating antibiotics, would be an appropriate threshold for treatment, and would improve upon current practice of antibiotic utilization.

Rietveld RP, et al. BMJ USA. 2004;4: 511-514.

Angiotensin-Receptor Blockade vs Converting-Enzyme Inhibition in Type 2 Diabetes and Nephropathy

The most common etiology of end-stage renal disease remains type 2 diabetes (DM2). Since it is possible to reverse (in the case of diabetic microalbuminuria) or delay (in the case of frank diabetic nephropathy) deterioration of renal function by means of good blood pressure control and/or modulation of the rennin-angiotensin-aldosterone system, clinicians continually seek evidence based guidance about best therapeutic choices.

This prospective double blind study randomized patients (n = 250) with early nephropathy to either an ARB (telmisartan 80 mg/d) or ACE inhibitor (enalapril 20 mg/d). Endpoints included decline in renal function, rates of end-stage renal disease, cardiovascular events, and mortality.

At the end of five years, telmisartan was found to be not inferior to enalapril for the primary study end point (decline in renal function); similarly, for all other pre-defined endpoints, there was no demonstrable statistically significant difference between the treatments. This information strengthens the support for the equivalence of ACE and ARB in addressing preservation of renal function in diabetes. Preference for either class of agent may depend upon cost, tolerability, or effectiveness for other therapeutic targets, since both drugs performed equally well.

Barnett AH, et al. N Engl J Med. 2004;351:1952-1961.

Dr. Kuritzky, Clinical Assistant Professor, University of Florida, Gainesville, is Associate Editor of Internal Medicine Alert.