Saudi Journal of Obesity

: 2018  |  Volume : 6  |  Issue : 1  |  Page : 25--28

Effect of laparoscopic sleeve gastrectomy on metabolic and nutritional changes at King Abdulaziz University Hospital, Saudi Arabia

Rawan Alsolami1, Wisam H Jamal2, Yara A Fayoumi1, Sarah A Almaghrabi1, Murad M Aljiffry3, Mohammad M Zagzoog1,  
1 Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
2 Department of Surgery, Jeddah University, Saudi Arabia
3 Department of Surgery, Faculty of Medicine, King Abdulaziz University, Jeddah, Jeddah, Saudi Arabia

Correspondence Address:
Dr. Wisam H Jamal
Assistant professor of general surgery, Department of Surgery, University of Jeddah, Jeddah
Saudi Arabia


Introduction: Bariatric surgery has been shown to be the most effective way to treat obesity. The outcome of weight-loss surgeries primarily focuses on reducing weight, and improving comorbidities and quality of life of patients. Postoperative nutritional deficiencies are well known complications of sleeve gastrectomy. Deficiencies of protein, iron, and vitamins B12 and D are often reported and may occur despite supplementation. Aim: The aim of this study was to assess the effect of laparoscopic sleeve gastrectomy on metabolic and nutritional changes among obese patients at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. Methods and Subjects: This is a retrospective review of patients who underwent sleeve gastrectomy surgery between January 2013 and January 2016 at KAUH, Jeddah, Saudi Arabia. Perioperative characteristics, biochemical profile [glycated hemoglobin (HbA1c), calcium, parathyroid (PTH), albumin, B12, lipid, and iron profile], and details on subsequent weight loss in terms of body mass index (BMI) and weight loss (kg) of the patients were obtained. Results: Sixty-six patients were included in the study. Forty-two (63.4%) were female with a mean age of 35.1 ± 10.3 years. Our results demonstrated a significant statistical reduction in weight and BMI with improvement in HbA1c, high-density lipoprotein, triglycerides, and low-density lipoprotein, and decrease in cholesterol level. On the contrary, other metabolic elements such as ferritin and vitamin B12 showed a significant decrease, whereas calcium, PTH hormone, and albumin showed no change. Conclusion: This study showed that sleeve gastrectomy had significant improvements of some biochemical markers in addition to reduction in weight and BMI.

How to cite this article:
Alsolami R, Jamal WH, Fayoumi YA, Almaghrabi SA, Aljiffry MM, Zagzoog MM. Effect of laparoscopic sleeve gastrectomy on metabolic and nutritional changes at King Abdulaziz University Hospital, Saudi Arabia.Saudi J Obesity 2018;6:25-28

How to cite this URL:
Alsolami R, Jamal WH, Fayoumi YA, Almaghrabi SA, Aljiffry MM, Zagzoog MM. Effect of laparoscopic sleeve gastrectomy on metabolic and nutritional changes at King Abdulaziz University Hospital, Saudi Arabia. Saudi J Obesity [serial online] 2018 [cited 2021 Dec 2 ];6:25-28
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Full Text


Obesity is defined as a body mass index (BMI) of greater than 30 kg/m2 and is associated with multiorgan dysfunctions.[1] It is one of the most common community conditions worldwide, which results from intake of specific food choices, frequency of eating, and luxury lifestyles.[2] Nowadays, bariatric surgery (BS) has been shown to be the most effective way to treat obesity.[3] Despite the advantages of sleeve gastrectomy, there are multiple nutritional and metabolic complications postoperatively.[4] In the gastrointestinal tract, calcium is absorbed in the duodenum. Bypassing the duodenum may lead to malabsorption of calcium and secondary hyperparathyroidism. Vitamin D plays an important role in calcium and phosphorus homeostasis.[5] The wide expansion of these procedures is to manage metabolic conditions such as type 2 diabetes mellitus (T2DM) and dyslipidemia.[6] However, the aim of BS mainly focuses on reducing weight, and improving comorbidities and quality of life of patients. Postoperative nutrition deficiencies are one of the most common complications of BS. Deficiencies of protein, iron, and vitamins B12 and D are often reported and may occur despite supplementation.[7] The effect of laparoscopic sleeve gastrectomy (LSG) on metabolic and nutritional changes among obese patients was assessed at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia.


We retrospectively reviewed all patients who underwent LSG in our center from January 2013 to January 2016, performed by a single surgical team in KAUH, Jeddah, Saudi Arabia. Patients were excluded from the study if they had American Society of Anesthesiologists’ classification of Physical Health score 4 and more, or a history of major medical problems, such as mental impairment, being pregnant, malignant neoplasm, or missing data. Patients were eligible for the LSG if they had a BMI of 40 kg/m2 or a BMI between 35 and 40 kg/m2 with obesity-related comorbidities, such as T2DM, hypertension (HTN), disk prolapse, and sleep apnea. Both informed and written consent were obtained from each patient.

The first postoperative follow-up was performed 2 weeks after the surgery. The routine follow-ups were scheduled at 6 and 12 months, and then yearly. Upon discharge, all patients were prescribed multivitamins and iron supplements (Centrum, Fefol, Caltrate, Ursofalk, vitamin D, and Neurobion). The study protocol was reviewed and approved by the Health Research and Ethical Board at KAUH and the Biomedical Research Ethics Unit at King Abdulaziz University.

Anthropometric parameters

Weight of the study patients was measured by calibrated seca scale (Itin Scale Co., Inc., Germany) with the precision of 0.1 g and height by a cotton ruler. The BMI was calculated as weight (kg)/height squared (m2).

Clinical and biological assessment

After an overnight fasting, serum blood (10 mL) was collected by venipuncture between 8.00 a.m. and 10.00 a.m. ethylenediaminetetraacetic acid (EDTA) plasma samples were centrifuged for 7.5 min at 4°C within 10 min following taking of blood sample. Vitamin 25(OH)D, vitamin B12, and transferrin were detected in serum samples. Plasma was analyzed for ferritin, calcium, and albumin. Samples were immediately sent to the local laboratory for analysis.

Biochemical parameters were measured using routine techniques. Hematologic profiles were determined by using an automatic cell counter (Excell-18; Drew Scientific, St Paul, Minnesota, USA). Blood 25(OH)D was determined by enzyme immunoassay (Immunodiagnostic Systems GmbH, Frankfurt, Germany). Glycated hemoglobin (HbA1c) was determined by glucose oxidase–peroxidase method by using the procedure as described by Trinder (REF: 10260; Vitamin B12 was assayed by a competitive immunoassay using direct chemiluminescence technology (ADVIA Centaur System, Siemens AG, Deerfield, Illinois, USA). Ferritin, calcium, albumin, and transferrin were determined using the ADVIA 1650. Total cholesterol, triacylglyceride, and high-density lipoprotein (HDL) were analyzed by enzymatic colorimetric method (REF: 10017, REF: 10720P, REF: 10084). Serum low-density lipoprotein (LDL) was determined by the method described by Okada et al. (REF: 10094; The level of parathyroid (PTH) hormone was evaluated in IRMA (DIAsource, Belgium).

Deficiencies were defined as a concentration below the reference interval: HbA1c 4.2 to 6.3%, hemoglobin 12.0 to 15.0 g/dL, 25(OH)D 75.0 to 250.0 nmol/L, ferritin 13.0 to 150.0 ng/mL, transferrin 2.0 to 3.6 g/L, cholesterol 0.0 to 5.2 mmol/L, triglycerides 0.3 to 2.30 mmol/L, LDL 0.0 to 3.57 mmol/L, HDL 0.9 to 1.55 mmol/L, B12 187 to 974 pmol/L, calcium 2.12 to 2.52 mmol/L, PTH 1.18 to 8.43 pmol/L, and albumin 40.2 to 47.6 g/L.

Statistical analyses

Data collection was performed via an electronic database (Phoenix), and statistical analysis was performed using Statistical Package for the Social Sciences (SPSS, Version 17.0; Chicago, Illinois, USA). Student’s paired sample t-test was used for comparisons between paired measurements. The linear regression model was used to study the relationship between outcome variables. A P-value of less than 0.05 was considered statistically significant.


A total of 72 patients underwent LSG as a primary procedure in KAUH. Six patients were excluded due to missing data, and 66 patients (42 females, 24 males) with full data were included in the study. The mean age was 35.3 ± 10.3 years, mean weight was 125.5 ± 26.9 kg and mean BMI was 46.3 ± 7.9 kg/m2. All patients successfully completed the 2 years follow-up for weight loss. Metabolic and nutritional changes of the patients at 6 months, and 1 and 2 years of follow-up after surgery is shown in [Table 1].{Table 1}

Weight loss outcomes

Postoperative weight loss (kg) and BMI reduction were observed at all follow-up assessment points (M6, M12, and M24). This is demonstrated. The BMI (kg/m2) decreased from 46.3 ± 7.9 to 36.62 ± 7.1, 33.2 ± 10.9, and 28.7 ± 6.8 at 6, 12, and 24 months, respectively. Weight loss (kg) was from 125.5 ± 26.9 to 97.7 ± 23.4, 84.7 ± 19.5, and 75.5 ± 16.1 at 6, 12, and 24 months, respectively [Table 1].

Glycemic profile

The mean of HbA1c significantly decreased from preoperative (6.2 ± 1.7) to postoperative at 2 years of follow-up (5.5 ± 0.6) (P = 0.001) [Table 1].

Lipid profile

No significant differences were found in the cholesterol levels, but there was significant improvement of triglyceride, LDL, and HDL (P value < 0.0001) [Table 1].

Iron profile

There was no significant difference in hemoglobin (P value = 0.317). However, a drop of ferritin level throughout the study period was reported with significant differences (P = 0.002) and an increase in transferrin level at 2 years of follow-up (P < 0.0001) [Table 1].

Metabolic and nutritional changes

A significant increase in vitamin D was noted throughout the follow-up period with P value < 0.0001. B12 levels increased slightly after 6 months postoperative and then started to decline till they reached 306.5 ± 137.8 with significant differences. There were significant changes in albumin, calcium, and PTH levels [Table 1].


Bariatric surgical procedures have been shown to be among the most effective long-term weight reduction techniques and can reduce the risks of morbidity and mortality and increase life expectancy.[8] In this study, 66 patients underwent sleeve gastrectomy over a 2-year period. The majority of the participants were females, and 22.7% of the patients had T2DM; in contrast to another study performed at Johns Hopkins on 58 patients, most of them were diabetics (42.0%).[9] In our study, weight reduction and BMI in the 2 years of follow-up were 75.5 ± 16.1 kg and 28.7 ± 6.8 kg/m2, respectively. In another study that was performed at Aseer study, the mean weight loss (130–80 kg) and the BMI reduction (42–32 kg/m2) were measured only at 1-year intervals.[1] In addition, this study showed significant statistical decreases in both ferritin and vitamin B12 levels (48.9 ± 30.2 and 306.5 ± 137.8, respectively), although vitamin B12 levels were identified as being deficient both before and after the LSG comparing to a study performed by Damms-Machado et al.[10] in Germany.

Furthermore, when we studied the vitamin D, calcium, HDL, and transferrin levels, significant increases in almost all follow-up settings were reported. In contrast to these findings, a study conducted by Damms-Machado et al.[10] reported postoperative vitamin D deficiency in more than 50% of the patients; HDL was significantly increased from 49.9 ± 15.1 to 61.5 ± 18.7 mg/dL (all P < 0.001) whereas transferrin deficiency was detected in two patients.The current study showed higher preoperative levels of cholesterol, triglycerides, and LDL when compared to a study performed by Bawahab et al.[2] in Aseer region. However, significant improvement in the cholesterol, triglyceride, and LDL levels was reported during the postoperative follow-ups. In addition, HbA1c levels showed a significant improvement, although there is a paucity in the literature regarding HbA1c among morbidly obese patients who had T2DM before surgery.[11] Cholesterol level were reduced without any significant changes, showing 4.6 ± 0.8. In comparison to Aseer’s study,[2] another study concluded that patients after BS suffer mainly from vitamin B12, iron, protein, and vitamin D deficiencies.[12] Patients in this study showed a slight increase in vitamin B12 level 6 months postoperative and then started to decline till it reached 306.5 ± 137.8, whereas there was an increase in vitamin D, which could be due to the prescribed multivitamin supplements after operations.


In this study, sleeve gastrectomy have been shown to be associated with significant biochemical changes in various systems of the body, which indicate the importance of regular postoperative follow-up to identify and correct such deficiencies which may lead to serious metabolic and nutritional complications.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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