A Meta-Analytic Structural Equation Modeling (meta-SEM) for the Changes in Body Mass Index (BMI), Apnea-Hypopnea Index (AHI), and Oxygen Saturation (SPO2) after Bariatric Surgery

Eghbali, F; Ahmadi, SAY; Jahanshahi, F; Madankan, A; Jaliliyan, A; Mosavari, H; Bighdeli, AH

A Meta-Analytic Structural Equation Modeling (meta-SEM) for the Changes in Body Mass Index (BMI), Apnea-Hypopnea Index (AHI), and Oxygen Saturation (SPO2) after Bariatric Surgery

Authors

F Eghbali ¹

SAY Ahmadi ²

F Jahanshahi ³

A Madankan ⁴

A Jaliliyan ⁵

H Mosavari ³

AH Bighdeli ⁶

¹ Associate Professor, Department of General Surgery, Iran University of Medical Sciences, Surgical Research Center, Rasoul Akram Hospital (PBUH)

² Research Assistant and General Physician, Iran University of Medical Sciences, Preventive Medicine and Population Health Research Center

³ General Physician, Iran University of Medical Sciences, Surgical Research Center, Rasoul Akram Hospital (PBUH)

⁴ Assistant Professor, Department of General Surgery, Iran University of Medical Sciences, Surgical Research Center, Rasoul Akram Hospital (PBUH)

⁵ Research Assistant and General Physician, General Physician, Iran University of Medical Sciences, Surgical Research Center, Rasoul Akram Hospital (PBUH)

⁶ Resident of General Surgery, Iran University of Medical Sciences, Rasoul Akram Hospital, Tehran, Iran

Abstract

Introduction & Objective: In spite of the existence of evidence regarding the role of bariatric surgery on body mass index (BMI) reduction, improving apnea-hypopnea index (AHI) and enhancement of oxygen saturation (SPO2), there was no evidence regarding a causal network of these variables. The present study was aimed to investigate the associations using structural equation modeling (SEM). Materials & Methods: A secondary study was conducted using SEM on the aggregate data of the literature. A directed acyclic graph (DAG) was designed and SEM was performed for verification of the hypothesized DAG at P < 0.1. This graph included BMI as an independent variable, percentage of oxygen saturation as a dependent variable, and AHI as a mediating variable. Results: A total of 684 cases were studied. On the average, 12.1 kg/m2 reduction was observed for BMI, 20.0 unit reductions was observed for AHI and 2.1% increase was observed for Mean of SPO2. According to SEM, the effect of reducing the BMI on the reduction of the AHI was positive (effect coefficient = 0.28; that is, a decrease of one unit in the BMI led to a decrease of 0.28 units in the AHI) and the effect of decreasing the AHI was also positive on improving the average percentage of oxygen saturation (effect coefficient = 0.13; i.e., a decrease of one unit in the AHI led to an improvement of 0.13 units in the average percentage of oxygen saturation). Thus, the product of these two paths showed that in the indirect path, each unit reduction in body mass index leads to a 0.04% improvement in the average percentage of oxygen saturation. The coefficient of the direct path was 0.07, which means that the contribution of the mediating path to the total effect is 0.335 (about one third). Conclusions: AHI changes were associated with BMI changes, but the association of SPO2 changes with BMI and AHI changes were not tangible. It seems that the variation of SPO2 changes may be explained by some other variables.

Keywords

Obesity

Obstructive Sleep Apnea

Metabolic Surgery

Meta-Analysis

Statistical Modeling

1. Meurling IJ, Shea DO, Garvey JF. Obesity and sleep: a growing concern. Curr Opin Pulm Med. 2019 Nov; 25(6): 602-8.

2. Powell TA, Mysliwiec V, Brock MS, Morris MJ. OSA and cardiorespiratory fitness: a review. J Clin Sleep Med. 2022 Jan; 18(1): 279-88.

3. Lao M, Cheng Y, Gao X, Ou Q. The interaction among OSA, CPAP, and medications in patients with comorbid OSA and cardiovascular/cerebrovascular disease: a randomized controlled trial. BMC Pulm Med. 2022 Dec; 22(1): 99.

4. Salman LA, Shulman R, Cohen JB. Obstructive Sleep Apnea, Hypertension, and Cardiovascular Risk: Epidemiology, Pathophysiology, and Management. Curr Cardiol Rep. 2020 Feb; 22(2): 6.

5. Yaggi HK, Concato J, Kernan WN, Lichtman JH, Brass LM, Mohsenin V. Obstructive Sleep Apnea as a Risk Factor for Stroke and Death. N Engl J Med. 2005 Nov 10; 353(19): 2034-41.

6. Blackwell JN, Walker M, Stafford P, Estrada S, Adabag S, Kwon Y. Sleep Apnea and
Sudden Cardiac Death. Circ Rep. 2019 Dec 10; 1(12): 568-74.

7. Valezi AC, Herbella FAM, Schlottmann F, Patti MG. Gastroesophageal Reflux Disease in Obese Patients. J Laparoendosc Adv Surg Tech. 2018 Aug; 28(8):
949-52.

8. Jeong HG, Cho S, Ryu KJ, Kim T, Park H. Effect of weight loss before in vitro fertilization in women with obesity or overweight and infertility: a systematic review and meta-analysis. Sci Rep. 2024 Mar 14; 14(1): 6153.

9. Al-shoaibi AAA, Li Y, Song Z, Hong YJ, Chiang C, Nakano Y, et al. Associations of overweight and obesity with the risk of cardiovascular disease according to metabolic risk factors among
middle-aged Japanese workers: The Aichi Workers’ cohort study. Obes Res Clin Pract. 2024 Mar; S1871403X24000127.

10. Prattichizzo F, Ceriello A, Shah VN. Obesity, NAFLD/NASH, and Diabetes. Diabetes Technol Ther. 2024 Mar 1; 26(S1): S-231-S-240.

11. Dixit M, Pawar S, Saket S. Obstructive Sleep Apnea Hypopnea Syndrome among Obese Patients Visiting the Outpatient Department of a Tertiary Care Centre. J Nepal Med Assoc. 2024 Jan 2; 62(269): 37-9.

12. Jackson TN, Cox BP, Grinberg GG, Yenumula PR, Lim RB, Chow GS, et al. National usage of bariatric surgery for class I obesity: an analysis of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program. Surg Obes Relat Dis. 2023 Nov; 19(11): 1255-62.

13. Talmant J, Talmant JC, Deniaud J, Amat P. Du traitement étiologique des apnées obstructives du sommeil. Orthod Fr. 2019 Sep; 90(3-4): 423-8.

14. Iannella G, Magliulo G, Greco A, De
Vincentiis M, Ralli M, Maniaci A, et al.
Obstructive Sleep Apnea Syndrome: From Symptoms to Treatment. Int J Environ Res Public Health. 2022 Feb 21; 19(4): 2459.

15. Wyszomirski K, Walędziak M, Różańska-Walędziak A. Obesity, Bariatric Surgery and Obstructive Sleep Apnea-A Narrative Literature Review. Medicina (Mex). 2023 Jul 7; 59(7): 1266.

16. Peromaa-Haavisto P, Luostarinen M,
Juusela R, Tuomilehto H, Kössi J. Obstructive
Sleep Apnea: The Effect of Bariatric Surgery
After Five Years-A Prospective Multicenter
Trial. Obes Surg [Internet]. 2024 Mar 8
[cited 2024 Mar 16]; Available from: https://link.springer.com/10.1007/s11695-024-07124-5.

17. Locke BW, Gomez-Lumbreras A, Tan CJ, Nonthasawadsri T, Veettil SK, Patikorn C, et al. The association of weight loss from anti-obesity medications or bariatric surgery and apnea-hypopnea index in obstructive sleep apnea. Obes Rev. 2024 Feb 11; obr. 13697.