High blood pressure after weight loss surgery

1. Hypertension (HTN) remission, as defined in established guidelines, measured using a mercury sphygmomanometer twice on the left arm for a minimum of 30 seconds while the patient was seated on a chair and using the Korotkoff sound technique at pre-surgery, 3-, 6-, 12-, 18-, 24-, and 36-months post-surgery.
HTN was defined as systolic blood pressure (SBP) equal to or above 140 mm Hg or diastolic blood pressure (DBP) equal to or above 90 mm Hg. In patients with preoperative HTN, remission was identified on the day on which the patient met all of the following three criteria:
1.1. SBP <140 mm Hg
1.2. DBP <90 mm Hg
1.3. Discontinuation of antihypertensive drugs

2. HTN relapse, which due to the lack of a clear definition was defined as the deterioration of HTN remission, measured using a mercury sphygmomanometer twice on the left arm for a minimum of 30 seconds while the patient was seated on a chair and using the Korotkoff sound technique at pre-surgery, 3-, 6-, 12-, 18-, 24-, and 36-months post-surgery.
Relapse in the patients who experienced remission after bariatric surgery was defined as follows:
2.1. The need for prescribing any antihypertensive drug regardless of BP
2.2. SBP ≥ 140 mm Hg or DBP ≥ 90 mm Hg

3. Biochemical parameters in blood samples collected between 7 and 9 am after 12 to 14 hours of overnight fasting were measured on the same day:
3.1. Fasting plasma glucose, as measured using the enzymatic colorimetric method at pre-surgery, 3-, 6-, 12-, 18-, 24-, and 36-months post-surgery
3.2. Serum triglyceride, as measured using the enzymatic colorimetric method at pre-surgery, 3-, 6-, 12-, 18-, 24-, and 36-months post-surgery
3.3. Total cholesterol, as measured using the enzymatic colorimetric method at pre-surgery, 3-, 6-, 12-, 18-, 24-, and 36-months post-surgery
3.4. High-density lipoprotein-cholesterol, as measured after precipitation of apolipoprotein B-containing lipoproteins with phosphotungstic acid at pre-surgery, 3-, 6-, 12-, 18-, 24-, and 36-months post-surgery
3.5. Low-density lipoprotein-cholesterol, as measure using serum total cholesterol, triglyceride, and high-density lipoprotein-cholesterol concentrations at pre-surgery, 3-, 6-, 12-, 18-, 24-, and 36-months post-surgery. (Friedewald formula: LDL cholesterol = total cholesterol - HDL - (triglycerides / 5))
3.6. Hemoglobin A1C, as measured using affinity chromatographic method at pre-surgery, 3-, 6-, 12-, 18-, 24-, and 36-months post-surgery

The relationship between remission and relapse of HTN was measured using a Cox regression analysis of risk factors such as:
1. Smoking measured using a questionnaire (never, past, current smoker) at baseline
2. Diabetes as defined as fasting plasma glucose ≥ 126 mg/dl or hemoglobin A1C ≥ 6.5 or current medication therapy for a definite diagnosis of diabetes at baseline
3. Lack of appropriate weight loss after surgery measured using EWL < 70% at one tear after surgery (EWL% = [Initial weight - Postop weight] / [Initial weight - Ideal weight] * 100)
4. Old age measured using a questionnaire (more than 45 years) at baseline
5. High consumption of antihypertensive drugs was measured using a questionnaire (more than two antihypertensive drugs) at baseline