Branched-chain α-ketoacid dehydrogenase deficiency (maple syrup urine disease): Treatment, biomarkers, and outcomes

Over the past three decades, we studied 184 individuals with 174 different molecular variants of branched-chain α-ketoacid dehydrogenase activity, and here delineate essential clinical and biochemical aspects of the maple syrup urine disease (MSUD) phenotype. We collected data about treatment, survival, hospitalization, metabolic control, and liver transplantation from patients with classic (i.e., severe; n = 176), intermediate (n = 6) and intermittent (n = 2) forms of MSUD. A total of 13,589 amino acid profiles were used to analyze leucine tolerance, amino acid homeostasis, estimated cerebral amino acid uptake, quantitative responses to anabolic therapy, and metabolic control after liver transplantation. Standard instruments were used to measure neuropsychiatric outcomes. Despite advances in clinical care, classic MSUD remains a morbid and potentially fatal disorder. Stringent dietary therapy maintains metabolic variables within acceptable limits but is challenging to implement, fails to restore appropriate concentration relationships among circulating amino acids, and does not fully prevent cognitive and psychiatric disabilities. Liver transplantation eliminates the need for a prescription diet and safeguards patients from life-threatening metabolic crises, but is associated with predictable morbidities and does not reverse pre-existing neurological sequelae. There is a critical unmet need for safe and effective disease-modifying therapies for MSUD which can be implemented early in life. The biochemistry and physiology of MSUD and its response to liver transplantation afford key insights into the design of new therapies based on gene replacement or editing.

Association of Mobile Patient Portal Access With Diabetes Medication Adherence and Glycemic Levels Among Adults With Diabetes

IMPORTANCE

Online patient portals support self-management, and mobile devices expand portal access, but whether this translates to improvements in diabetes outcomes is unclear.

OBJECTIVE

To examine the association of adding mobile patient portal access with diabetes medication adherence and glycemic levels among adults with diabetes.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included patients with diabetes treated at Kaiser Permanente Northern California, a large, integrated health care delivery system, from April 1, 2015, to December 31, 2017. Inclusion criteria were adults with diabetes with an oral diabetes prescription at baseline and no insulin use. Data were analyzed from March 2018 to March 2019.

EXPOSURES

Patient portal access status for each calendar month from April 2015 to December 2017, categorized as never used, used from a computer only, used from a mobile device only, or used from both computer and mobile device.

MAIN OUTCOMES AND MEASURES

Medication adherence, measured by monthly percentage of days covered (PDC), and glycemic levels, measured by changes in glycated hemoglobin A1c (HbA1c) levels. The association of portal access with study outcomes was assessed using linear regression with patient-level fixed effects and adjusting for time-changing variables, stratified by baseline HbA1c level.

RESULTS

Among 111 463 included patients (mean [SD] age, 63.79 [12.93] years; 59 918 [53.76%] men), the number of patients using the portal from both a computer and mobile device increased over time from 38 371 patients (34.42%) in April 2015 to 57 920 patients (61.71%) in December 2017. Among patients with no prior portal access, adding computer-only portal access was associated with an increase in PDC of 1.16 (95% CI, 0.63 to 1.70) percentage points and a change of -0.06 (95% CI, -0.08 to -0.03) percentage points in HbA1c level, and adding both mobile and computer portal access was associated with an increase in PDC of 1.67 (95% CI, 1.10 to 2.23) percentage points and a change of -0.13 (95% CI, -0.16 to -0.10) percentage points in HbA1c level. Among patients with higher baseline HbA1c level (>8.0%), changing from no portal access to both computer and mobile access was associated with an increase in PDC of 5.09 (95% CI, 3.78 to 6.40) percentage points and a change of -0.19 (95% CI, -0.27 to -0.15) percentage points in HbA1c level.

CONCLUSIONS AND RELEVANCE

These findings suggest that providing patients with computer patient portal access and combining it with mobile patient portal access are associated with significantly improved diabetes medication adherence and glycemic control, with greater benefits among patients with more clinical need. Convenient access to portal self-management tools through a mobile device could significantly improve diabetes management.

Biochemical correlates of neuropsychiatric illness in maple syrup urine disease

Maple syrup urine disease (MSUD) is an inherited disorder of branched chain amino acid metabolism presenting with neonatal encephalopathy, episodic metabolic decompensation, and chronic amino acid imbalances. Dietary management enables survival and reduces risk of acute crises. Liver transplantation has emerged as an effective way to eliminate acute decompensation risk. Psychiatric illness is a reported MSUD complication, but has not been well characterized and remains poorly understood. We report the prevalence and characteristics of neuropsychiatric problems among 37 classical MSUD patients (ages 5-35 years, 26 on dietary therapy, 11 after liver transplantation) and explore their underlying mechanisms. Compared with 26 age-matched controls, MSUD patients were at higher risk for disorders of cognition, attention, and mood. Using quantitative proton magnetic resonance spectroscopy, we found lower brain glutamate, N-acetylaspartate (NAA), and creatine concentrations in MSUD patients, which correlated with specific neuropsychiatric outcomes. Asymptomatic neonatal course and stringent longitudinal biochemical control proved fundamental to optimizing long-term mental health. Neuropsychiatric morbidity and neurochemistry were similar among transplanted and nontransplanted MSUD patients. In conclusion, amino acid dysregulation results in aberrant neural networks with neurochemical deficiencies that persist after transplant and correlate with neuropsychiatric morbidities. These findings may provide insight into general mechanisms of psychiatric illness.