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Raoof, Mustafa
Publications (4 of 4) Show all publications
Cao, Y., Raoof, M., Montgomery, S., Ottosson, J. & Näslund, I. (2019). Predicting Long-Term Health-Related Quality of Life after Bariatric Surgery Using a Conventional Neural Network: A Study Based on the Scandinavian Obesity Surgery Registry. Journal of clinical medicine, 8(12), Article ID E2149.
Open this publication in new window or tab >>Predicting Long-Term Health-Related Quality of Life after Bariatric Surgery Using a Conventional Neural Network: A Study Based on the Scandinavian Obesity Surgery Registry
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2019 (English)In: Journal of clinical medicine, E-ISSN 2077-0383, Vol. 8, no 12, article id E2149Article in journal (Refereed) Published
Abstract [en]

Severe obesity has been associated with numerous comorbidities and reduced health-related quality of life (HRQoL). Although many studies have reported changes in HRQoL after bariatric surgery, few were long-term prospective studies. We examined the performance of the convolution neural network (CNN) for predicting 5-year HRQoL after bariatric surgery based on the available preoperative information from the Scandinavian Obesity Surgery Registry (SOReg). CNN was used to predict the 5-year HRQoL after bariatric surgery in a training dataset and evaluated in a test dataset. In general, performance of the CNN model (measured as mean squared error, MSE) increased with more convolution layer filters, computation units, and epochs, and decreased with a larger batch size. The CNN model showed an overwhelming advantage in predicting all the HRQoL measures. The MSEs of the CNN model for training data were 8% to 80% smaller than those of the linear regression model. When the models were evaluated using the test data, the CNN model performed better than the linear regression model. However, the issue of overfitting was apparent in the CNN model. We concluded that the performance of the CNN is better than the traditional multivariate linear regression model in predicting long-term HRQoL after bariatric surgery; however, the overfitting issue needs to be mitigated using more features or more patients to train the model.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
Bariatric surgery, conventional neural network, deep learning, health-related quality of life, prediction
National Category
Surgery
Identifiers
urn:nbn:se:oru:diva-78544 (URN)10.3390/jcm8122149 (DOI)000506640400119 ()31817385 (PubMedID)
Note

Funding Agency:

Örebro Region County Council  OLL-864441

Available from: 2019-12-13 Created: 2019-12-13 Last updated: 2020-01-27Bibliographically approved
Raoof, M., Näslund, I., Rask, E. & Szabo, E. (2016). Effect of Gastric Bypass on Bone Mineral Density, Parathyroid Hormone and Vitamin D: 5 Years Follow-up. Obesity Surgery, 26(5), 1141-1145
Open this publication in new window or tab >>Effect of Gastric Bypass on Bone Mineral Density, Parathyroid Hormone and Vitamin D: 5 Years Follow-up
2016 (English)In: Obesity Surgery, ISSN 0960-8923, E-ISSN 1708-0428, Vol. 26, no 5, p. 1141-1145Article in journal (Refereed) Published
Abstract [en]

Background: The aim of the present study was to see if there are longitudinal changes in bone mineral density (BMD), vitamin D or parathyroid hormone (PTH) in females 5 years after Laparoscopic Roux-en-Y Gastric Bypass (LRYGB).

Methods: Thirty-two women with mean age 41.6 ± 9.3 years and mean body mass index (BMI) 44.5 ± 4.6 kg/m(2) were included. Preoperatively, 2 and 5 years postoperatively, BMD, weight, height, S-calcium, S-albumin, S-creatinine, S-25(OH)-vitamin D and fP-PTH were measured.

Results: The mean decrease in BMI between baseline and 5 years after surgery was 29.4 %. BMD of the spine and femur measured as z- and t-scores, showed a linear, statistically significant declining trend over the years. The fall in BMD of the spine and femoral neck between baseline and 5 years after surgery was 19 and 25 %, respectively. The mean fP-PTH showed a significant increase over the study period (20.2 μg/L increase, 95 % CI:-31.99 to -8.41). S-calcium, both free and corrected for albumin, showed a decrease between baseline and 5 years after surgery. Eight patients developed osteopenia and one osteoporosis after a 5-year follow-up.

Conclusion: LRYGB is an efficient method for sustained long-term body weight loss. There is, however, a concomitant decrease in BMD and S-calcium, and an increase in fP-PTH.

Place, publisher, year, edition, pages
New York, USA: Springer, 2016
Keywords
Bone mineral density, gastric bypass, BMI, parathyroid hormone, obesity, vitamin D
National Category
Endocrinology and Diabetes
Identifiers
urn:nbn:se:oru:diva-49206 (URN)10.1007/s11695-016-2114-3 (DOI)000374400900037 ()26926187 (PubMedID)2-s2.0-84959431689 (Scopus ID)
Available from: 2016-03-10 Created: 2016-03-10 Last updated: 2019-03-07Bibliographically approved
Raoof, M., Näslund, I., Rask, E., Karlsson, J., Sundbom, M., Edholm, D., . . . Szabo, E. (2015). Health-Related Quality-of-Life (HRQoL) on an Average of 12 Years After Gastric Bypass Surgery. Obesity Surgery, 25(7), 1119-1127
Open this publication in new window or tab >>Health-Related Quality-of-Life (HRQoL) on an Average of 12 Years After Gastric Bypass Surgery
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2015 (English)In: Obesity Surgery, ISSN 0960-8923, E-ISSN 1708-0428, Vol. 25, no 7, p. 1119-1127Article in journal (Refereed) Published
Abstract [en]

It is evident that morbidly obese patients have a low health-related quality-of-life (HRQoL), and this low HRQoL has become a common reason for them to seek bariatric surgery. Several HRQoL studies demonstrate a dramatic postoperative improvement, but most of these have had a short follow-up period.

An observational, cross-sectional study for HRQoL was conducted to study 486 patients (average age of 50.7 +/- 10.0 years, with 84 % of them being female) operated with gastric bypass (GBP) in the period 1993 to 2003 at the University Hospitals of A-rebro and Uppsala. Mean follow-up after gastric bypass was 11.5 +/- 2.7 years (range 7-17). Two HRQoL instruments were used, SF-36 and the Obesity-related Problems scale (OP). The study group was compared with two control groups, both matched for age and gender, one from the general population and one containing morbidly obese patients evaluated and awaiting bariatric surgery.

The study group scored better in the SF-36 domains (all four physical domains and the vitality subscore) and OP scale compared to obese controls, but their HRQoL scores were lower than those of the general population. HRQoL was better among younger patients and in the following subgroups: men, patients with satisfactory weight loss, satisfied with the procedure, free from co-morbidities and gastrointestinal symptoms, employment, good oral status and those not hospitalised or regularly followed up for non-bariatric reasons.

Long-term follow-up after GBP for morbid obesity showed better scores in most aspects of HRQoL compared to obese controls but did not achieve the levels of the general population. Patients with better medical outcome after gastric bypass operation had better HRQoL.

Keywords
Gastric bypass, Health-related quality-of-life, Long-term follow-up, SF-36, Morbid obesity
National Category
Surgery
Research subject
Surgery
Identifiers
urn:nbn:se:oru:diva-45292 (URN)10.1007/s11695-014-1513-6 (DOI)000355921600004 ()25566743 (PubMedID)2-s2.0-84930760360 (Scopus ID)
Available from: 2015-07-23 Created: 2015-07-20 Last updated: 2018-06-30Bibliographically approved
Berglind, D., Willmer, M., Eriksson, U., Thorell, A., Sundbom, M., Udden, J., . . . Rasmussen, F. (2015). Longitudinal assessment of physical activity in women undergoing Roux-en-Y gastric bypass. Obesity Surgery, 25(1), 119-125
Open this publication in new window or tab >>Longitudinal assessment of physical activity in women undergoing Roux-en-Y gastric bypass
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2015 (English)In: Obesity Surgery, ISSN 0960-8923, E-ISSN 1708-0428, Vol. 25, no 1, p. 119-125Article in journal (Refereed) Published
Abstract [en]

Background: Patients undergoing bariatric surgery do not seem to increase objectively measured physical activity (PA) after surgery, despite substantial weight loss. The aims of the present study were (i) to objectively characterize 3 months pre-surgery to 9 months postsurgery PA and sedentary behavior changes in women undergoing Roux-en-Y gastric bypass (RYGB) using tri-axial accelerometers and (ii) to examine associations between pre-surgery versus postsurgery PA and sedentary behavior with anthropometric measures taken in home environment.

Methods: Fifty-six women, with an average pre-surgery body mass index (BMI) of 37.6 (SD 2.6) and of age 39.5 years (SD 5.7), were recruited at five Swedish hospitals. PA was measured for 1 week by the Actigraph GT3X+ accelerometer, and anthropometric measures were taken at home visits 3 months pre-surgery and 9 months postsurgery, thus limiting seasonal effects.

Results: Average BMI loss, 9 months postsurgery, was 11.7 (SD 2.7) BMI units. There were no significant pre- to postsurgery differences in PA or sedentary behavior. However, pre-surgery PA showed negative association with PA change and positive association with postsurgery PA. Adjustments for pre-surgery BMI had no impact on these associations.

Conclusions: No significant differences were observed in objectively measured changes in PA or time spent sedentary from 3 months pre-surgery to 9 months postsurgery among women undergoing RYGB. However, women with higher pre-surgery PA decreased their PA postsurgery while women with lower pre-surgery PA increased their PA.

Keywords
Physical activity, Roux-en-Y gastric bypass, RYGB, Accelerometer, Longitudinal
National Category
Surgery
Research subject
Surgery
Identifiers
urn:nbn:se:oru:diva-42203 (URN)10.1007/s11695-014-1331-x (DOI)000346781300017 ()24934315 (PubMedID)2-s2.0-84902234652 (Scopus ID)
Funder
Novo Nordisk
Note

Funding Agencies:

Swedish Council for Working Life and Social Research 2008-0654

Stockholm County Council (ALF)

Karolinska Institutet Diabetes Theme center

National School in Caring Sciences at Karolinska Institutet (NFV)

Erling-Persson Family Foundation

Available from: 2015-01-26 Created: 2015-01-23 Last updated: 2017-12-05Bibliographically approved
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