New research was presented at ADA 2019, the 79th Scientific Sessions of American Diabetes Association, from June 7-11 in Los Angeles. The features below highlight some of the studies that emerged from the conference.
Cost Effectiveness of ACP Glycemic Control Guideline
In 2019, the American College of Physicians issued a new guideline on A1C targets for adults with type 2 diabetes, with potential implications on long-term health and economic outcomes. To evaluate the cost-effectiveness of the guideline, researchers estimated the long-term health and cost consequences of changes in A1C targets, compared with a status quo, among three patient groups affected by the new guideline: 1) those with an A1C level less than 6.5% on anti-diabetic medications other than metformin who would de-intensify to a target level of 7.0% to 8.0%; 2) those with A1C levels of 7.0% to 8.0% and a life expectancy of less than 10 years who would de-intensify to a target level greater than 8.0%; and 3) those with an A1C level greater than 8.0% and a life expectancy greater than 10 years who would intensify to a target level of 7.0% to 8.0%. The study team found that implementing the guideline would result in nearly 245,000 fewer cardiovascular events, 1.38 million quality-adjusted life years (QALYs) gained, and an increase of $3.6 billion in healthcare expenditure nationwide. De-intensifying treatment was estimated to save $8,656 at a cost of 0.122 QALYs for patients with a life expectancy of less than 10 years and $8,169 at a cost of 0.058 QALYs for those with an A1C less than 6.5%. Intensifying treatment for those with an A1C greater than 8.0% cost an additional $11,454 per 0.38 QALY gained.
Diabetes Remission Durable Over 2 Years
Prior observational studies suggest that beta cell functional mass inevitably decreases over time. To assess this after 2 years in a geographically defined subgroup of participants in the Diabetes Remission Clinical Trial who achieved initial remission after diet-induced weight loss, study investigators quantified their functional beta cell mass and estimated their insulin secretion rates along with those of an age- and gender-matched (after weigh loss) nondiabetic comparator (NDC) group. Median maximum rates of insulin secretion increased from 0.58 at baseline to 0.74 at 5 months, 0.94 at 12 months, and 0.94 at 24 months, which was comparable with rates in the NDC group. Median first phase insulin response increased in responders from 0.042 125 nmol/min/m2 at baseline to 0.108 nmol/min/m2 at 5 months, to 0.110 125 nmol/min/m2 at 12 months, and then 0.125 nmol/min/m2 at 24 months. Those who failed to maintain remission were characterized by more weight regain during months 5 to 24. In responders, mean A1C was 6.0% at 24 months.
High Complication Rates in Young Adults With Diabetes
The TODAY study, published in 2012, indicated that type 2 diabetes “was more aggressive in kids than in adults” and that the participants had a rapid loss of beta-cell function. Researchers performed follow-up analyses now that participants are at a mean age of 25 years and having had diabetes for a mean of 7.5 years. From 2011 to 2014, participants’ average BMI increased from 34.9 kg/m2 to 36.3 kg/m2, while A1C increased from 6.0% to 9.3%, with complication rates increasing steadily following an initial diagnosis of youth-onset type 2 diabetes. During up to 12 years of follow-up, the cumulative incidence rates of elevated LDL cholesterol and hypertension increased from 3% to 26%, and from 20% to 55%, respectively. There were 6.2 cardiovascular events per 1,000 patients per year during follow-up. Abnormal albumin excretion and hyperfiltration prevalence rates increased from 8% and 12%, respectively, at baseline, to 42% and 55%, respectively. Among those who had fundus photos taken in 20011 and 2018, “substantial” progression of diabetic retinopathy was observed. Among pregnancies, 11.9% ended in a miscarriage, 35.6% of expectant moms were hospitalized for maternal complications, 18.1% had preeclampsia, and 37.5% had maternal hypertension. Among babies from these pregnancies, 3.8% were stillborn, 23.7% were premature, 15.9% had very low birth weight, 18.9% had macrosomia, 28.7% had neonatal hypoglycemia, 14.0% had respiratory distress, and 8.5% had a cardiac anomaly.
Can Vitamin D Help Prevent Diabetes?
Although prior observational studies suggest an association between low blood 25-hydroxyvitamin D level and type 2 diabetes risk, whether vitamin D supplementation can help lower diabetes risk remains unknown. To asses this unknown, researchers randomized adults who met at least two of three glycemic criteria for prediabetes and no diagnostic criteria for diabetes to vitamin D3 4,000 IU per day or placebo, regardless of baseline serum 25-hydroxyvitamin D level. By month 24, mean serum 25-hydroxyvitamin D levels increased from 27.7 ng/mm at baseline to 54.3 ng/mm in the vitamin D group and from 28.2 ng/mm to 28.8 ng/mm in the placebo group. At a median follow-up of 2.5 years, the primary outcome of diabetes occurred at 9.39 events per 100 person-years in the vitamin D group and 10.66 events per 100 person-years in the placebo group. Adverse event incidence rates did not differ significantly between the groups. “Among persons at high risk for type 2 diabetes not selected for vitamin D insufficiency, vitamin D3 supplementation at a dose of 4000 IU per day did not result in a significantly lower risk of diabetes than placebo,” the study authors concluded.
The Impact of Intensive Lifestyle Intervention on A1C
Previous research suggests that weight loss in patients with diabetes and obesity through real-world intensive lifestyle intervention (ILI) is associated with significantly lower A1C for up to 5 years. With it remaining unclear whether baseline A1C impacts the magnitude of glycemic improvement in this population, study investigators evaluated over 5 years a cohort of patients with diabetes and obesity who were enrolled in a 12-week ILI program. Participants were divided into those with baseline A1C levels less than 7.5% (group A), 7.5-9.05 (group B), or greater than 9.0% (group C). When compared with baseline, body weight at 5 years decreased by 6.6 kg, 9.6 kg, and 8.3 kg in groups A, B, and C, respectively. A1C in group A decreased by 0.5% at 12 weeks but increased over the following 5 years by 0.1%, 1.2%, 0.3%, 0.4%, and 0.6%, respectively. In group B, A1C decreased by 1.1% at 12 weeks, was maintained significantly lower at 1 year by -0.5%, rose to baseline at 3 years, and was maintained at that level for up to 5 years. In group C, A1C decreased by 2.4% at 12 weeks, was maintained significantly lower at 1 year by 0.9%, rose to baseline at 3 years, and was maintained at that level for up to 5 years. The study authors suggest that their findings “may help clinicians use baseline A1C to set realistic long-term expectations for patients considering ILI.”