Bariatric Surgery for the Metabolic Syndrome: Magic Bullet or Not?

Improvement of heart rate variability after decreased insulin resistance after sleeve gastrectomy for morbidly obesity patients

BACKGROUND

Morbidly obese patients display both an autonomic nervous imbalance and impaired glucose metabolism, and both of these conditions can be partially reversed after bariatric surgery. The aim of the present study was to investigate changes in heart rate variability (HRV) and glucose metabolism in patients after laparoscopic sleeve gastrectomy (SG).

METHODS

Eighteen morbidly obese patients who underwent SG were examined before surgery and at 7, 30, 90, and 180 days after surgery. Indices of HRV included time-domain, frequency-domain, and nonlinear parameters. Glucose metabolism was evaluated by the measuring levels of insulin resistance, glycated hemoglobin (HbA(1c)), and gut hormones.

RESULTS

The study included 9 men and 9 women with a mean age of 34 years. In the HRV study, the average R-R interval, median R-R interval, standard deviation of the R-R intervals, root mean squared successive difference of the R-R intervals (RMSSD), and the number of pairs of successive normal-to-normal beat intervals that differed by>50 ms significantly increased at 180 days after surgery. Regarding the frequency-domain indices, the low frequency (LF)/high frequency (HF) ratio was more balanced at 90 days after SG compared with baseline, and increases in the total power, LF band, and HF band were observed at 180 days. The assessments of insulin resistance, glucose metabolism, and gut hormones revealed not only improvements in the homeostasis model assessment of insulin resistance and HbA1c levels but also increases in the levels of glucagon-like peptide-1 at 90 and 180 days after surgery compared with baseline. A multivariable regression model revealed significantly negative associations between the perioperative changes in HOMA-IR and changes in both the RMSSD and HF band.

CONCLUSIONS

SG leads to early improvements in insulin resistance and glucose metabolism that are followed by improvements in HRV indices. Improvements in insulin resistance were associated with increases in the RMSSD and HF band index, but the mechanism of these changes require further study.

Co-morbidity resolution in morbidly obese children and adolescents undergoing sleeve gastrectomy

BACKGROUND

Bariatric surgery is becoming important for the reversal of co-morbidities in children and adolescents. We previously reported the safety and efficacy of laparoscopic sleeve gastrectomy (LSG) in the pediatric population. However, evidence pertaining to the effect of LSG on co-morbidities in this age group is scarce. The objective of this study was to assess the remission and improvement of co-morbidities (dyslipidemia, hypertension, diabetes, and obstructive sleep apnea) after LSG in children and adolescents.

METHODS

Anthropometric changes, complications, remission, and improvement in co-morbidities were assessed over 3 years. OSA was diagnosed using the Pediatric Sleep Questionnaire (PSQ) and polysomnography and its resolution was assessed according to PSQ score alone. Diabetes, prediabetes, hypertension, prehypertension, and dyslipidemia were assessed using standard pediatric-specific definitions.

RESULTS

The review yielded 226 patients; 74 patients were prepubertal (5-12 yr of age, mean: 9.8±2.3), 115 adolescents (13-17 yr of age, mean: 15.4±1.7), and 37 were young adults (18-21 yr of age, mean: 19.2±.8). Overall mean age was 14.4±4.0 years (range: 4.94-20.99), and 50.4% were females. Mean body mass index (BMI) and BMI z score were 48.2±10.1 kg/m(2) and 2.99±.35, respectively. Mean BMI z score at 1, 2, and 3 years postoperative was 2.01±.87, 2.00±1.07, and 1.66±.65, respectively. Mean preoperative height was 158.0±15.1 cm, and at 1, 2, and 3 years postoperative, it was 160.3±13.4, 161.4±14.1, and 163.2±11.1, respectively. All patients at different age groups experienced normal growth velocity. Within 2 years of follow-up, 90.3% of co-morbidities were in remission or improved, 64.9% of which were within the first 3 months postoperatively. No further improvement or remission was observed beyond 2 years, and there was no recurrence up to 3 years in patients who were seen in follow-up. The lost to follow-up in each of the 3 years was 4.2%, 7.6%, and 15.3%, respectively.

CONCLUSION

LSG performed on children and adolescents results in remission or improvement of>90% of co-morbidities within 2 years after bariatric surgery with few complications, no mortality, and normal growth.