Metabolic Changes Associated With Weight Gain After Treatment of Achalasia

Background Achalasia is a disease characterized by the loss of the myenteric neurons that coordinate esophageal peristalsis and lower esophageal sphincter (LES) relaxation.1 As a result, there is aperistalsis of the esophagus and impaired LES relaxation after deglutition. The primary symptoms are dysphagia, regurgitation, and chest pain.

Weight loss is also common.2 Studies have shown weight loss occurring in between 35-69% of achalasia patients.3,4 One study reported that patients with Type II Achalasia were more likely to have weight loss than the other subtypes.5 Studies have also shown that patients with achalasia, even when not underweight, are at risk of malnutrition.6 Recently, studies have begun assessing the weight gain that occurs after successful treatment of achalasia.7-10 These studies have evaluated achalasia patients after laparoscopic Heller myotomy (LHM),7 peroral endoscopic myotomy (POEM),8,9 or a combination of treatment modalities.10 They have consistently shown significant weight gain after treatment, with many patients becoming overweight or obese.

However, the impact of this weight gain has not been objectively evaluated. Thus, to our knowledge, no studies have evaluated the cardiovascular or metabolic effects of this post-treatment weight gain.

Goals Therefore, we aim to evaluate the metabolic effects of post-treatment weight gain in in a cohort of achalasia patients undergoing treatment by assessing the relationship between weight gain and glycemic control, cholesterol levels, blood pressure, and hepatic steatosis.

Methods A prospective pilot study will be performed at both Shamir Medical Center and Hadassah Medical Center. All adult patients diagnosed with achalasia and undergoing either POEM or LHM for treatment of achalasia will be included.

The cases of achalasia will be reviewed thoroughly for demographic, clinical, laboratory, and manometric information.

Additionally, prior to POEM, the patient will be evaluated for:

• height, weight, and BMI;
• resting blood pressure;
• laboratory data including fasting glucose, Hgb A1c level, cholesterol panel, triglycerides, and liver function tests;
• Fibroscan (to measure hepatic steatosis and fibrosis).
• Eckhardt score
• Waist circumference
• Body fat percentage POEM or LHM will then be performed as indicated for achalasia treatment. One year after treatment, the initial testing will be repeated (including weight, blood pressure, fasting laboratory data, waist circumference, body fat percentage, and Fibroscan).

Statistical analyses Each patient's follow-up results will be compared to their pre-treatment results. Outcomes will include changes in levels of hepatic steatosis, waist circumference, body fat percentage, fasting glucose, Hgb A1c, cholesterol, liver function tests, and triglycerides compared to baseline, and the relationship in these changes to any weight gained. The primary outcome will be the change in hepatic steatosis on Fibroscan testing.

Continuous variables with a normal distribution will be reported as mean with standard deviation (SD), while those with a skewed distribution will be reported as median with interquartile range (IQR). Comparisons of categorical variables will be performed using the Chi-square test and Fisher's Exact test. Comparisons involving continuous variables will be performed using the Mann-Whitney U test. For all statistical calculations, a p-value \<0.05 will be considered statistically significant.