Bariatric Surgery Restores Cardiac and Sudomotor Autonomic C-Fiber Dysfunction towards Normal in Obese Subjects with Type 2 Diabetes

Abstract

ObjectiveThe aim was to evaluate the impact of bariatric surgery on cardiac and sudomotor autonomic C-fiber function in obese subjects with and without Type 2 diabetes mellitus (T2DM), using sudorimetry and heart rate variability (HRV) analysis.MethodPatients were evaluated at baseline, 4, 12 and 24 weeks after vertical sleeve gastrectomy or Roux-en-Y gastric bypass. All subjects were assessed using SudoscanTM to measure electrochemical skin conductance (ESC) of hands and feet, time and frequency domain analysis of HRV, Neurologic Impairment Scores of lower legs (NIS-LL), quantitative sensory tests (QST) and sural nerve conduction studies.ResultsSeventy subjects completed up to 24-weeks of follow-up (24 non-T2DM, 29 pre-DM and 17 T2DM). ESC of feet improved significantly towards normal in T2DM subjects (Baseline = 56.71±3.98 vs 12-weeks = 62.69±3.71 vs 24-weeks = 70.13±2.88, p<0.005). HRV improved significantly in T2DM subjects (Baseline sdNN (sample difference of the beat to beat (NN) variability) = 32.53±4.28 vs 12-weeks = 44.94±4.18 vs 24-weeks = 49.71±5.19, p<0,001 and baseline rmsSD (root mean square of the difference of successive R-R intervals) = 23.88±4.67 vs 12-weeks = 38.06±5.39 vs 24-weeks = 43.0±6.25, p<0.0005). Basal heart rate (HR) improved significantly in all groups, as did weight, body mass index (BMI), percent body fat, waist circumference and high-density lipoprotein (HDL). Glycated hemoglobin (HbA1C), insulin and HOMA2-IR (homeostatic model assessment) levels improved significantly in pre-DM and T2DM subjects. On multiple linear regression analysis, feet ESC improvement was independently associated with A1C, insulin and HOMA2-IR levels at baseline, and improvement in A1C at 24 weeks, after adjusting for age, gender and ethnicity. Sudomotor function improvement was not associated with baseline weight, BMI, % body fat or lipid levels. Improvement in basal HR was also independently associated with A1C, insulin and HOMA2-IR levels at baseline.ConclusionThis study shows that bariatric surgery can restore both cardiac and sudomotor autonomic C-fiber dysfunction in subjects with diabetes, potentially impacting morbidity and mortality.

The diagnostic usefulness of the combined COMPASS 31 questionnaire and electrochemical skin conductance for diabetic cardiovascular autonomic neuropathy and diabetic polyneuropathy

“…Moreover, correlations between ESC and morphology of small fibers have been reported by some authors using skin biopsy parameters although weaker than expected and denied by others using corneal confocal microscopy measures . Finally, ESC has been advocated as a sensitive outcome in an intervention study with bariatric surgery in subjects with prediabetes and type 2 diabetes, but also the associations between ESC and CARTs were inconsistent at 1‐year follow‐up in 37 subjects with type 1 diabetes and free of complications, and the ESC decline unrelated to clinical variables and standard autonomic measures . The position statement of the American Diabetes Association did not recommend routine screening for sudomotor dysfunction in clinical practice …”

“…Moreover, correlations between ESC and morphology of small fibers have been reported by some authors using skin biopsy parameters although weaker than expected 15,19,43 and denied by others using corneal confocal microscopy measures. 44 Finally, ESC has been advocated as a sensitive outcome in an intervention study with bariatric surgery in subjects with prediabetes and type 2 diabetes, 45 but also the associations between ESC and…”

Comparable Attenuation of Sympathetic Nervous System Activity in Obese Subjects with Normal Glucose Tolerance, Impaired Glucose Tolerance, and Treatment Naïve Type 2 Diabetes following Equivalent Weight Loss

“…Casellini et al (2016) measured time and frequency domain analysis of heart rate variability before and after surgical weight loss in non-diabetic, pre-diabetic, and T2D subjects. They reported that changes in cardiac autonomic function, representing both sympathetic and parasympathetic components, were significantly greater in T2D subjects.…”

“…This concurs with the known central sympathoexcitatory effects of insulin (Anderson et al, 1991; Rahmouni et al, 2004). Other studies have shown greater improvement in glycemic and cardiac autonomic indices in T2D subjects compared to normal glucose tolerant (NGT) subjects after lifestyle induced and surgical weight loss (Solomon et al, 2010; Casellini et al, 2016). Hitherto, the relative benefits of weight loss in obese subjects with different stages of glycemic control on robust assessments of SNS activity are unknown.…”

Medical and surgical management of obesity and diabetes: what's new?

“…A meta‐analysis of two studies ( n= 40 participants) that examined the effect of RYGB on peripheral neuropathy in type 2 diabetes and a BMI <35 kg/m 2 reported a significant reduction in the Neuropathy Symptoms Score and Neuropathy Disability Score 12 months after surgery [effect size −3.830 (95% CI −4.234 to −3.426); P <0.001 and −2.174 (95% CI −3.093 to −1.255); P <0.0001, respectively) . A similar effect on Neuropathy Disability Score has been observed in 17 morbidly obese patients with type 2 diabetes over 24 weeks after sleeve gastrectomy and RYGB [effect size −1.188 (95% CI −1.651 to −0.726); P <0.0001] . Indeed, a recent systematic review and meta‐analysis of 420 obese participants undergoing bariatric surgery showed a significant improvement in the International Index of Erectile Function score, sexual desire, sexual intercourse satisfaction, and total satisfaction .…”