Polarity- and Intensity-Independent Modulation of Timing During Delay Eyeblink Conditioning Using Cerebellar Transcranial Direct Current Stimulation.

Delay eyeblink conditioning (dEBC) is widely used to assess cerebellar-dependent associative motor learning, including precise timing processes. Transcranial direct current stimulation (tDCS), noninvasive brain stimulation used to indirectly excite and inhibit select brain regions, may be a promising tool for understanding how functional integrity of the cerebellum influences dEBC behavior. The aim of this study was to assess whether tDCS-induced inhibition (cathodal) and excitation (anodal) of the cerebellum differentially impact timing of dEBC. A standard 10-block dEBC paradigm was administered to 102 healthy participants. Participants were randomized to stimulation conditions in a double-blind, between-subjects sham-controlled design. Participants received 20-min active (anodal or cathodal) stimulation at 1.5 mA (n = 20 anodal, n = 22 cathodal) or 2 mA (n = 19 anodal, n = 21 cathodal) or sham stimulation (n = 20) concurrently with dEBC training. Stimulation intensity and polarity effects on percent conditioned responses (CRs) and CR peak and onset latency were examined using repeated-measures analyses of variance. Acquisition of CRs increased over time at a similar rate across sham and all active stimulation groups. CR peak and onset latencies were later, i.e., closer to air puff onset, in all active stimulation groups compared to the sham group. Thus, tDCS facilitated cerebellar-dependent timing of dEBC, irrespective of stimulation intensity and polarity. These findings highlight the feasibility of using tDCS to modify cerebellar-dependent functions and provide further support for cerebellar contributions to human eyeblink conditioning and for exploring therapeutic tDCS interventions for cerebellar dysfunction.

The roles of type 2 diabetes and obesity in disease activity and progression of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis.

OBJECTIVE: We examined the roles of type 2 diabetes (T2D) and obesity in disease activity and fibrosis progression/regression in patients with non-alcoholic fatty liver disease/non-alcoholic steatohepatitis (NAFLD/NASH). METHODS: This multi-center, retrospective study included patients with suspected or histologically proven NAFLD/NASH from the NASH Clinical Research Network. Outcomes included disease activity and rate of fibrosis, assessed using liver-biopsy driven measures (NAFLD activity score [NAS] and fibrosis score [FS]). Logistic regression and doubly robu estimation of causal effects tested relationships among T2D, obesity, and NAFLD/NASH. RESULTS: The analytical sample included 870 adult patients with baseline biopsy data and 157 patients with multiple biopsy data. Patients with NAFLD/NASH and T2D had significantly higher baseline average NAS (4.52 vs. 4.13; p = 0.009) and FS (2.17 vs. 1.56; p < 0.0001); those with T2D had a significantly greater reduction in average NAS over time (-0.77/year vs. -0.17/year; p = 0.0008). Change in FS over time did not differ significantly by T2D status (-0.23/year vs. -0.04/year; p = 0.34). Baseline NAS, baseline FS, and change in average NAS over time did not differ significantly by obesity status (4.17 vs. 4.47; p = 0.16; 1.73 vs.1.92; p = 0.31; -0.40/year vs. -0.59/year; p = 0.62, respectively). Patients with obesity had a slight increase in FS but those without obesity had a reduction in average FS over time (0.07/year vs. -0.27/year; p = 0.008). CONCLUSIONS: Patients with NAFLD/NASH and T2D had greater baseline disease activity versus those without T2D, but there was greater regression of disease activity over time among those with T2D. Patients with NAFLD/NASH and obesity had worsening of fibrosis versus those without obesity. NCT00063622.

Gaps Remain for Achieving HbA1c Targets for People with Type 1 or Type 2 Diabetes Using Insulin: Results from NHANES 2009-2020.

INTRODUCTION: Glycated hemoglobin A1c (HbA1c) is an important measure to assess glycemic control and predict diabetes complications. However, there is limited information on trends in HbA1c among people with diabetes (PwDs) who use insulin. The aim of this study was to describe trends in HbA1c among PwDs who use insulin by diabetes type and insulin regimen. METHODS: A retrospective analysis was conducted using data from the National Health and Nutrition Examination Survey (NHANES, 2009-2020). PwDs were classified into three cohorts: type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus using mealtime insulin (T2DM-MTI), and type 2 diabetes mellitus (T2DM) using basal-only insulin (T2DM basal-only). Trends in HbA1c over time were assessed using regression analysis after adjusting for age, gender, and race/ethnicity. RESULTS: Mean HbA1c values aggregated over 2009-2020 were 8.0% (T1DM), 8.6% (T2DM-MTI), and 8.6% (T2DM basal-only). The American Diabetes Association-recommended target of HbA1c of < 7% was achieved by 25.2% of people in the T1DM and T2DM-MTI groups each and by 12.3% of people in the T2DM basal-only group. Over time, an upward trend was observed in the percentage of people achieving HbA1c < 7% in the T2DM basal-only group. The percentage of PwDs achieving individualized HbA1c targets was 27.0%, 12.4%, and 16.1% for the T1DM, T2DM-MTI, and T2DM basal-only groups, respectively. CONCLUSIONS: Our study using NHANES data suggests that approximately 25% of PwDs achieve glycemic targets. This study highlights the need for improved therapies to better manage glycemic targets in PwDs.