Clinical Briefs

By Louis Kuritzky, MD, Clinical Assistant Professor, University of Florida, Gainesville. Dr. Kuritzky is an advisor for Endo, Kowa, Pricara, and Takeda.

Predictive Value of Postprandial Glucose for CV Events in Type 2 Diabetes

Source: Cavalot F, et al. Postprandial blood glucose predicts cardiovascular events and all-cause mortality in type 2 diabetes in a 14-year follow-up: Lessons from the San Luigi Gonzaga Diabetes Study. Diabetes Care 2011;34:2237-2243.

The decode data (diabetes epidemiology Collaborative Analysis of Diagnostic Criteria in Europe) indicated that all-cause mortality, as well as cardiovascular (CV) events, were better predicted by postprandial glucose (PPG) than fasting blood glucose (FPG). Indeed, the DECODE data set indicates a linear rise in relative risk for mortality as one progresses from normoglycemia, to impaired glucose tolerance, to frank diabetes.

Although much of the literature is consistent in finding that PPG outperforms both FPG and A1C in predicting adverse CV events (and mortality), one criticism aimed at these data reminds us that PPG data were, for the most part, obtained from oral glucose tolerance testing (OGTT). Since only a small minority of patients outside clinical trials actually have OGTT performed, obtaining a PPG after actual meals might better reflect the pathophysiology occurring in long-term management of diabetics.

Cavalot et al report on a 14-year follow-up of type 2 diabetes patients (n = 505) in whom A1C, FPG, and PPG (not obtained by OGTT) were measured at baseline, seeking to discern the relationship of each of these metrics with CV events and overall mortality.

For mortality as well as CV events, both A1C and PPG were strong predictors (especially post-lunch PPG). FPG was not a good predictor. It remains to be determined whether interventions specifically targeting PPG will provide meaningful benefit beyond simple traditional diabetes control.

Lifetime Risk of Developing COPD: A Longitudinal Population Study

Source: Gershon AS, et al. Lifetime risk of developing chronic obstructive pulmonary disease: A longitudinal population study. Lancet 2011;378:991-996.

Worldwide, chronic obstructive pulmonary disease (COPD) is the fourth most common cause of death, and is predicted to become the third most common cause in the near future, especially if smoking habits in populous nations like China — where more than half of adult men are currently smokers — continue on their same trajectory. According to Gershon et al, no prior publications have provided adequate insight into the lifetime risk of developing COPD. Hence, using health administrative data from the entire population of Ontario, Canada (n = approximately 13 million), they reported on a 14-year follow-up of persons who did not have COPD at baseline.

Based on the window of observation from 1996-2010, the population was divided categorically into: a) physician-diagnosed COPD, b) reached age 80 without a COPD diagnosis, or c) death. By age 80, more than one-fourth (28%) of persons free of COPD at baseline had been diagnosed with COPD by a physician. To put this into perspective, a new diagnosis of COPD was more likely than congestive heart failure, acute myocardial infarction, or even diabetes.

The authors mention that they have observed less public awareness of COPD than might be merited based on its epidemiological presence, and they encourage greater energies be invested in smoking cessation and public education about COPD.

The Burden of Painful Diabetic Peripheral Neuropathy

Source: Abbott CA, et al. Prevalence and characteristics of painful diabetic neuropathy in a large community-based diabetic population in the U.K. Diabetes Care 2011;34:2220-2224.

Recently published telephone surveys of large populations of diabetics indicate a low level of recognition of the diagnostic terminology "Diabetic Neuropathy," despite commonplace problematic symptoms consistent with this disorder. Diabetic peripheral neuropathy (DPN) and diabetic peripheral neuropathic pain (DPNP) are associated with major morbidities. For instance, the leading cause of amputation in diabetics is foot ulcer subsequent to impaired sensation in the feet from diabetic neuropathy. Similarly, DPNP is often worsened by activity, which tends to compromise exercise capacity and may also interrupt sleep.

The North-West Diabetes Foot Care Study screened 15,692 adult diabetics in northwest England. The presence of neuropathy was established using scoring systems as well as specific nerve function testing (vibration, pin-prick, temperature, and reflex testing). Screenings took place during routine annual evaluations by primary care clinicians.

Overall, one-third of study subjects experienced painful neuropathy. DPNP was twice as common in persons with type 2 diabetes than type 1. Women and persons of South Asian ethnicity were disproportionately affected. Based on these findings, clinicians might anticipate an important positive yield from routinely screening for symptoms of DPNP and signs of DPN.