Review of Metformin Use for Type 2 Diabetes Prevention.

CONTEXT: Prediabetes is prevalent and significantly increases lifetime risk of progression to type 2 diabetes. This review summarizes the evidence surrounding metformin use for type 2 diabetes prevention. EVIDENCE ACQUISITION: Articles published between 1998 and 2017 examining metformin use for the primary indication of diabetes prevention available on MEDLINE. EVIDENCE SYNTHESIS: Forty articles met inclusion criteria and were summarized into four general categories: (1) RCTs of metformin use for diabetes prevention (n=7 and n=2 follow-up analyses); (2) observational analyses examining metformin use in heterogeneous subgroups of patients with prediabetes (n=9 from the Diabetes Prevention Program, n=1 from the biguanides and the prevention of the risk of obesity [BIGPRO] trial); (3) observational analyses examining cost effectiveness of metformin use for diabetes prevention (n=11 from the Diabetes Prevention Program, n=1 from the Indian Diabetes Prevention Program); and (4) real-world assessments of metformin eligibility or use for diabetes prevention (n=9). Metformin was associated with reduced relative risk of incident diabetes, with the strongest evidence for use in those at highest risk (i.e., aged <60 years, BMI ≥35, and women with histories of gestational diabetes). Metformin was also deemed cost effective in 11 economic analyses. Recent studies highlighted low rates of metformin use for diabetes prevention in real-world settings. CONCLUSIONS: Two decades of evidence support metformin use for diabetes prevention among higher-risk patients. However, metformin is not widely used in real-world practice, and enhancing the translation of this evidence to real-world practice has important implications for patients, providers, and payers.

Overweight/obesity and gastric fluid characteristics in pediatric day surgery: implications for fasting guidelines and pulmonary aspiration risk.

BACKGROUND: The safety of 2-h preoperative clear liquid fasts has not been established for overweight/obese pediatric day surgical patients. Healthy children and obese adults who fasted 2 h have small residual gastric fluid volumes (GFVs), which are thought to reflect low pulmonary aspiration risk. We sought to measure the prevalence of overweight/obesity in our day surgery population. We hypothesized that neither body mass index (BMI) percentile nor fasting duration would significantly affect GFV or gastric fluid pH. In children who were allowed clear liquids up until 2 h before surgery, we hypothesized that overweight/obese subjects would not have increased GFV over lean/normal subjects and that emesis/pulmonary aspiration events would be rare. METHODS: Demographics, medical history, height, and weight were recorded for 1000 consecutive day surgery patients aged 2-12 yr. In addition, 1000 day surgery patients (age 2-12 yr) undergoing general endotracheal anesthesia were enrolled. After tracheal intubation, a 14-18F orogastric tube was inserted and gastric contents evacuated. Medications, fasting interval, GFV, pH, and emetic episodes were documented. Age- and gender-specific Center for Disease Control and Prevention growth charts (2000) were used to determine ideal body weight (IBW = 50th percentile) and to classify patients as lean/normal (BMI 25th-75th percentile), overweight (BMI > or = 85th to <95th percentile), or obese (BMI > or = 95th percentile). RESULTS: Of all day surgery patients, 14.0% were overweight and 13.3% were obese. Obese children had lower GFV per total body weight (P < 0.001). When corrected for IBW, however, volumes GFV(IBW) were identical across all BMI categories (mean 0.96 mL/kg, sd 0.71; median 0.86 mL/kg, IQR 0.96). Preoperative acetaminophen and midazolam contributed to increased GFV(IBW) (P = 0.025 and P = 0.001). Lower GFV(IBW) was associated with ASA physical status III (P = 0.024), male gender (P = 0.012), gastroesophageal reflux disease (P = 0.049), and proton pump inhibitor administration (P = 0.018). GFV(IBW) did not correlate with fasting duration or age. Decreased gastric fluid acidity was associated with younger age (P = 0.005), increased BMI percentile (P = 0.036), and African American race (P = 0.033). Emesis on induction occurred in eight patients (50% of whom were obese, P = 0.052, and 75% of whom had obstructive sleep apnea, P = 0.061). Emesis was associated with increased ASA physical status (P = 0.006) but not with fasting duration. There were no pulmonary aspiration events. CONCLUSIONS: Twenty-seven percent of pediatric day surgery patients are overweight/obese. These children may be allowed clear liquids 2 h before surgery as GFV(IBW) averages 1 mL/kg regardless of BMI and fasting interval. Rare emetic episodes were not associated with shortened fasting intervals in this population.

Parachute mitral valve: morphologic descriptors, associated lesions, and outcomes after biventricular repair.

OBJECTIVE: In "true" parachute mitral valve, mitral valve chordae insert into one papillary muscle. In parachute-like asymmetric mitral valve, most or all chordal attachments are to one papillary muscle. This study compared morphologic features, associated lesions, and palliation strategies of the two parachute mitral valve and dominant papillary muscle types and examined interventions and midterm outcomes in patients with biventricular circulation. METHODS: Echocardiography and autopsy databases were reviewed to identify patients with "true" parachute mitral valve or parachute-like asymmetric mitral valve from January 1987 to January 2006. Predictors of palliation strategy in the entire cohort, mitral stenosis on initial echocardiogram, and mortality in the biventricular cohort were determined with logistic regression. RESULTS: Eighty-six patients with "true" parachute mitral valve (n = 49) or parachute-like asymmetric mitral valve (n = 37) were identified. Chordal attachments to the posteromedial papillary muscle were more common (73%). The presence "true" parachute mitral valve (P = .008), hypoplastic left ventricle (P < .001), and two or more left-sided obstructive lesions (P = .002) predicted univentricular palliation. Among 49 patients maintaining biventricular circulation at follow-up, 8 died median follow-up 6.4 years (7 days-17.8 years). Multivariate analysis revealed that "true" parachute mitral valve was associated with mitral stenosis on initial echocardiogram (P = .03), and "true" parachute mitral valve (P = .04) and conotruncal anomalies (P = .0003) were associated with mortality. Progressive mitral stenosis was found in 11 patients; 2 underwent mitral valve interventions, and 1 died. CONCLUSION: Nearly two thirds of this parachute mitral valve cohort underwent biventricular palliation. Some progression of mitral stenosis occurred, although mitral valve intervention was rare. "True" parachute mitral valve was associated with mitral stenosis on initial echocardiogram. "True" parachute mitral valve and conotruncal anomalies were associated with mortality in the biventricular population.