Factors predictive of severe hypoglycemia in type 1 diabetes: analysis from the Juvenile Diabetes Research Foundation continuous glucose monitoring randomized control trial dataset.

Diabetes care (Impact Factor: 7.74). 03/2011; 34(3):586-90. DOI: 10.2337/dc10-1111
Source: PubMed

ABSTRACT Identify factors predictive of severe hypoglycemia (SH) and assess the clinical utility of continuous glucose monitoring (CGM) to warn of impending SH.
In a multicenter randomized clinical trial, 436 children and adults with type 1 diabetes were randomized to a treatment group that used CGM (N = 224), or a control group that used standard home blood glucose monitoring (N = 212) and completed 12 months of follow-up. After 6 months, the original control group initiated CGM while the treatment group continued use of CGM for 6 months. Baseline risk factors for SH were evaluated over 12 months of follow-up using proportional hazards regression. CGM-derived indices of hypoglycemia were used to predict episodes of SH over a 24-h time horizon.
The SH rate was 17.9 per 100 person-years, and a higher rate was associated with the occurrence of SH in the prior 6 months and female sex. SH frequency increased eightfold when 30% of CGM values were ≤ 70 mg/dL on the prior day (4.5 vs. 0.5%; P < 0.001), but the positive predictive value (PPV) was low (<5%). Results were similar for hypoglycemic area under the curve and the low blood glucose index calculated by CGM.
SH in the 6 months prior to the study was the strongest predictor of SH during the study. CGM-measured hypoglycemia over a 24-h span is highly associated with SH the following day (P < 0.001), but the PPV is low.

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    ABSTRACT: BACKGROUND: Severe hypoglycemia is a major complication of insulin treatment in patients with type 1 diabetes, limiting full realization of glycemic control. It has been shown in the past that low levels of hemoglobin A1c (HbA1c), a marker of average plasma glucose, predict a high risk of severe hypoglycemia, but it is uncertain whether this association still exists. Based on advances in diabetes technology and pharmacotherapy, we hypothesized that the inverse association between severe hypoglycemia and HbA1c has decreased in recent years. METHODS AND FINDINGS: We analyzed data of 37,539 patients with type 1 diabetes (mean age ± standard deviation 14.4±3.8 y, range 1-20 y) from the DPV (Diabetes Patienten Verlaufsdokumentation) Initiative diabetes cohort prospectively documented between January 1, 1995, and December 31, 2012. The DPV cohort covers an estimated proportion of >80% of all pediatric diabetes patients in Germany and Austria. Associations of severe hypoglycemia, hypoglycemic coma, and HbA1c levels were assessed by multivariable regression analysis. From 1995 to 2012, the relative risk (RR) for severe hypoglycemia and coma per 1% HbA1c decrease declined from 1.28 (95% CI 1.19-1.37) to 1.05 (1.00-1.09) and from 1.39 (1.23-1.56) to 1.01 (0.93-1.10), respectively, corresponding to a risk reduction of 1.2% (95% CI 0.6-1.7, p<0.001) and 1.9% (0.8-2.9, p<0.001) each year, respectively. Risk reduction of severe hypoglycemia and coma was strongest in patients with HbA1c levels of 6.0%-6.9% (RR 0.96 and 0.90 each year) and 7.0%-7.9% (RR 0.96 and 0.89 each year). From 1995 to 2012, glucose monitoring frequency and the use of insulin analogs and insulin pumps increased (p<0.001). Our study was not designed to investigate the effects of different treatment modalities on hypoglycemia risk. Limitations are that associations between diabetes education and physical activity and severe hypoglycemia were not addressed in this study. CONCLUSIONS: The previously strong association of low HbA1c with severe hypoglycemia and coma in young individuals with type 1 diabetes has substantially decreased in the last decade, allowing achievement of near-normal glycemic control in these patients. Please see later in the article for the Editors' Summary.
    PLoS Medicine 10/2014; 2014 Oct 7;11(10):e1001742. doi: 10.1371/journal.pmed.1001742. eCollection 2014 Oct.. · 15.25 Impact Factor
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    ABSTRACT: OBJECTIVE Optimizing glycemic control in type 1 diabetes is important to minimize the risk of complications. We used the large T1D Exchange Clinic Registry database to identify characteristics and diabetes management techniques in adults with type 1 diabetes, differentiating those under excellent glycemic control from those with poorer control.RESEARCH DESIGN AND METHODS The cross-sectional analysis included 627 participants with HbA1c <6.5% (excellent control) and 1,267 with HbA1c ≥8.5% (fair/poor control) at enrollment who were ≥26 years of age (mean ± SD 45.9 ± 13.2 years), were not using continuous glucose monitoring, and had type 1 diabetes for ≥2 years (22.8 ± 13.0 years).RESULTSCompared with the fair/poor control group, participants in the excellent control group had higher socioeconomic status, were more likely to be older and married, were less likely to be overweight, were more likely to exercise frequently, and had lower total daily insulin dose per kilogram (P < 0.0001 for each). Excellent control was associated with more frequent self-monitoring of blood glucose (SMBG), giving mealtime boluses before a meal rather than at the time of or after a meal, performing SMBG before giving a bolus, and missing an insulin dose less frequently (P < 0.0001 for each). Frequency of severe hypoglycemia was similar between groups, whereas diabetic ketoacidosis was more common in the fair/poor control group.CONCLUSIONS Diabetes self-management related to insulin delivery, glucose monitoring, and lifestyle tends to differ among adults with type 1 diabetes under excellent control compared with those under poorer control. Future studies should focus on modifying diabetes management skills in adult type 1 diabetes patients with suboptimal glycemic control.
    Diabetes care 09/2013; · 7.74 Impact Factor
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    ABSTRACT: Context:Few studies have assessed factors associated with severe hypoglycemia (SH) and diabetic ketoacidosis (DKA) in adults with type 1 diabetes (T1D).Objective:Determine frequency of and factors associated with the occurrence of severe hypoglycemia (SH) and diabetic ketoacidosis (DKA) in adults with type 1 diabetes.Design:Cross-sectional analysis from the T1D Exchange clinic registry.Setting:70 U.S. endocrinology centersPatients:Analysis included 7,012 participants in the T1D Exchange clinic registry aged 26-93 years old with T1D for ≥ 2 years.Results:Higher frequencies of SH and DKA were associated with lower socio-economic status (SES) (p<0.001). SH was strongly associated with diabetes duration (p<0.001), with 18.6% of those with diabetes ≥40 years having an event in the past 12 months. SH frequency was lowest in those with HbA1c levels of 7.0% (53 mmol/mol) to 7.5% (58 mmol/mol), being higher in those with HbA1c levels <7.0% (<53 mmol/mol) or >7.5% (>58 mmol/mol). DKA frequency increased with higher HbA1c levels (p<0.001), with 21.0% of those with HbA1c ≥10.0% (≥86 mmol/mol) having an event in the past 12 months.Conclusions:SH and DKA are more common in those with lower SES. DKA, most common in those with HbA1c ≥10.0% (≥86 mmol/mol), should be largely preventable. In contrast, SH, most frequent with diabetes ≥40 years duration, cannot be abolished given the limitation of current therapies. To reduce SH in adults with longstanding diabetes, consideration should be given to modifying HbA1c goals, particularly in patients with very low HbA1c levels.
    The Journal of Clinical Endocrinology and Metabolism 06/2013; · 6.31 Impact Factor

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