Obesity is one of the leading health problems in the world today with more than 13% of world’s population suffering from obesity. More than one-third of the U.S. adults’ communities are currently obese. The alarming rate at which children and adolescents are becoming overweight and obese due to dietary and lifestyle changes also calls for concern.
The projection is that by the year 2025 the total number of obese infants and young children will rise to 70million globally. Thus, with the rising prevalence of obesity among children and adolescents, the prevalence in adults would not likely reduce in the nearest future if drastic weight loss solutions were not put in place.
The leading cause of death globally is cardiovascular diseases. This is closely followed by cancers. Obesity is a risk factor for cardiovascular disease and cancers, and thus, obese individuals have higher chances of dying earlier than their colleagues with a healthy weight. Obesity-associated disease conditions such as hypertension, sleep apnea, diabetes mellitus, dyslipidemia, are all risk factors for cardiovascular diseases.
All these circumstances also impact negatively on the quality of life of an obese patient. Overweight individuals (BMI 25-29.9kg/m2) between the ages of 50 to 71 years have 20-40% increased the risk of death when compared with healthy-weight people of the same age. Obese patients have their own risk tripled. Research comparing obese and healthy-weight people revealed that a morbidly obese man of
25 years old would live for 12 years lesser than his age mate with a healthy weight.
Losing weight is not as easy as gaining weight. Most obese individuals find it difficult to achieve significant weight loss with diet and exercise. This is not unconnected with their inability to achieve a negative energy balance that will result to the mobilization of the stored fat for energy production. Their appetite has been increased beyond normal.
All these necessitated a surgical approach to achieve significant weight loss and reversal of the comorbid conditions, aimed at improving the quality of life and overall survival.
Bariatric surgeries are weight loss surgeries for morbidly obese patients and those who have not been able to achieve satisfactory weight loss with diet and exercise. There are restrictive as well as malabsorptive operations. The restrictive surgeries (gastric sleeve, lap band) reduce the capacity of the stomach to limit calorie intake while the malabsorptive procedures reduce the effective absorptive surface of the small intestine. Some operations combine both mechanisms (gastric bypass, duodenal switch).
Bariatric surgery has two key benefits: weight loss and reversal of comorbid conditions. All other
benefits are derived from these two.
Weight-Loss with Bariatric Surgery
Table of Contents of Page
- 1 Weight-Loss with Bariatric Surgery
- 2 Reversal of comorbid conditions
- 3 Details on Benefits of Bariatric Surgery
- 4 Cardiovascular diseases
- 5 Cancers
- 6 Diabetes mellitus
- 7 Dyslipidemia
- 8 Osteoarthritis
- 9 Infertility and irregular menses
- 10 Obstructive sleep apnea
- 11 Gallbladder disease
- 12 Liver disease
- 13 Gastro-esophageal reflux disease (GERD)
- 14 Psychological problems
- 15 Prolonged survival
The primary aim of performing bariatric surgery is to lose weight. Virtually all types of bariatric surgeries are effective in inducing weight loss with moderate differences between them. A patient can lose up to 40-90% of the excess weight by one-year post-surgery depending on the procedure performed. Duodenal switch induces the highest weight loss, followed by gastric bypass and then gastric sleeve surgery with lap band having the least.
- Gastric Sleeve Weight Loss Expectation
- Gastric Bypass Weight Loss Expectation
- Gastric Balloon Weight Loss Expectation
Reversal of comorbid conditions
- Diabetes mellitus: type 2 diabetes mellitus is present in many obese individuals with its attendant complications. All bariatric surgeries have demonstrated a reversal/improvement in this condition with many patients achieving a reasonable level of HbA1C and no longer needing anti-diabetic drugs while some may convert from insulin to anti-diabetic medications.
- Hypertension: this is another disease condition that is often associated with obesity. After bariatric surgery, full resolution/reduction in blood pressure occurs with most patients reducing the number and dosage of their antihypertensive drugs.
- Osteoarthritis: this is a generative disease that commonly affects synovial joint. Obesity is a known risk factor for osteoarthritis with knee osteoarthritis common in them. Weight loss that occurs after bariatric surgery helps reduce the pressure on the knee with improvement in the symptoms of this condition.
- Asthma: obese patients with asthmatic symptoms before bariatric surgery often show a reduction in the number and severity of exacerbations and this is accompanied by a decrease in controller medications such as corticosteroid thereby avoiding its attendant complications.
- Dyslipidemia: Dyslipidemia is a condition characterized by elevated levels of abnormal and low levels of healthy lipids. It is a risk factor for atherosclerosis (narrowing of vessel wall due to fat deposition) which in turn is an independent risk factor for cardiovascular events such as myocardial infarction (heart attack) or stroke. Following bariatric surgery, the blood lipid profile improves with a reduction in cardiovascular risk.
- Sleep apnea: obese patient experience obstructive sleep apnea; a condition characterized by temporary cessation of breath during sleep leading to poor sleep at night and drowsiness during the day. It may also be a risk factor for depression. Some patients have it so severe that they are placed on continuous positive airway pressure (CPAP) machine while asleep. However, all of them usually discontinue CPAP after bariatric surgery.
- Fertility: one of the problems of obese females is infertility (inability to achieve pregnancy). Polycystic ovarian syndrome (PCOS) may be a cause of infertility in them and most often improve after surgery.
- Cancer: abdominal obesity is a risk factor for the development of diseases. Bariatric surgery induces weight loss and reduces the chance of developing a malignancy.
Other benefits of bariatric surgery are derived from a combination of the above. After bariatric surgery, the patient will lose weight; self-esteem/self-image will be high, will no longer experience discrimination or rejection, enjoy quality sleep and therefore will not be depressed.
Improvement/complete resolution of disease conditions will reduce cardiovascular risks, improve quality of life, and increase the overall survival.
Details on Benefits of Bariatric Surgery
Obesity is defined based on the relationship between the weight (in kilograms) and the height (in meters) of an individual. A body mass index ≥30kg/m2 is regarded as obesity. With about 13% of the world’s population having a BMI ≥30kg/m2 and more significant than one-third of the US citizens falling in this category, obesity is no doubt a significant health problem.
Bariatric surgery is the primary curative solution to the rising prevalence of obesity among adults and adolescents. It does not only offer a means of losing weight but also provide a solution to the health problems associated with obesity.
The current weight loss surgeries began from the observation by Kremen et al. in 1954. Part of the small intestine of a dog was resected, and this was followed by a significant weight loss. This finding was supported by weight loss in people who lost part of their small intestine even with consumption of more calories. However, apart from weight loss, numerous health benefits are seen after bariatric surgery.
The health benefits of bariatric surgery can only be appreciated by first understanding numerous health problems associated with obesity. Below are the various health problems related to obesity and the health benefits of bariatric surgery as regards those disease conditions:
Obese person (before bariatric surgery)
After bariatric surgery (with healthy weight)
Elevated blood pressure
Reduction in both systolic and diastolic blood pressures
High abnormal cholesterol level
Reduction in bad cholesterol and increase in beneficial cholesterol
Increased risk of stroke
Reduction in the risk of stroke
Increased risk of myocardial infarction
Reduction in the risk of myocardial infarction
Increased risk of heart failure
Reduction in the risk of heart failure
Insulin resistance and diabetes mellitus
Complete resolution OR
Improvement with good blood sugar control and reduced need for medications
Increased incidence of cancers such as endometrial, breast, pancreas, liver, and colonic tumours
Reduced risks of cancers
Osteoarthritis of joint pain, deformity and reduced walk time
Reduced joint pain and increase in walk time
Menstrual irregularities, anovulatory cycle, polycystic ovarian syndrome,
Normalization of regular menses, ovulation, improvement in fertility with an increased chance of pregnancy and live birth
Snoring and poor sleep from obstructive sleep apnea and may need CPAP machine to sleep
Resolution of sleep apnea, withdrawal from CPAP machine
Gall stone often removed during gastric bypass surgery surgery
Heartburn, nausea, and vomiting from GERD
Improvement in GERD following gastric bypass
Fatty liver with increased risk of liver cirrhosis and liver cancer
Reversal of the fatty liver disease
Depression, anxiety, and other psychological symptoms
Improved mental health, improved self-esteem and satisfactory body image
Increased risk of dying and therefore reduced lifespan
Reversal of mortality risks, prolonged survival and improved quality of life
Many disease conditions have been linked directly or indirectly with obesity. The major ones are cardiovascular diseases. Obesity serves as a risk factor for hypertension, stroke, heart failure, ischemic heart disease, and other cardiovascular health problems. It is also important to mention that cardiovascular diseases are among the leading causes of death globally.
Hypertension has been found to improve after bariatric surgery with a reduction in both systolic and diastolic pressure. About 20-40% of patients recorded complete resolution of hypertension at 2years following bariatric surgery (Benraouane & Litwin, 2011). Those that do not have full resolution had significant improvement with reduction in the need for antihypertensive drugs. In another study, about 71% of patients showed complete resolution/improvement after gastric sleeve surgery (Hoyuela, 2017).
Another major health problem is the development of diseases. High-fat diet and obesity are known risk factors for many malignancies such as breast cancer, prostate cancer, colonic cancer, endometrial cancer, liver cancer, etc.
Obese patients who had bariatric surgery between 2005 and 2012 were followed-up till 2104 in a study. This included 22,198 patients who had bariatric surgery and 66,427 patients as controls. The incidence of cancer was then observed in them. It was found out that those who had bariatric surgery had a 33% reduction in cancer development compared with the controls. The chance of developing breast cancer, colon cancer, pancreatic cancer, endometrial cancer were all lowered in post-bariatric surgery patients than in obese patients who had no surgery (Schauer et al., 2017).
Type 2 diabetes mellitus, though can be seen in people of healthy weight, it is commonly a problem of the obese people. Obesity has been shown to be a cause of insulin resistance in this group of people making the endogenous insulin less efficient with the gradual exhaustion of the insulin-producing cells in the pancreas. The complications of diabetes include kidney damage (diabetic nephropathy), eye disease (diabetic retinopathy, maculopathy, and cataract), and neurological impairment (diabetic neuropathy). Other complications include leg ulcer, erectile dysfunction, recurrent infections, etc.
Many studies have shown improvement in diabetes and insulin resistance following bariatric surgery. About 80% of patients recorded a complete resolution with regular blood sugar and glycated hemoglobin and no need for medications and (Benraouane & Litwin, 2011). The resolution of diabetes mellitus is partly due to changes in gastrointestinal hormonal with their effects on metabolism.
In another study, a complete resolution of type 2 diabetes mellitus was recorded in 75% of patient who had gastric sleeve surgery after 12months. They had a blood sugar within standard limit after discontinuation of anti-diabetic drugs (Hoyuela, 2017).
In the STAMPEDE trial at Cleveland Clinic, 42% of obese patient who had gastric sleeve surgery had their glycated hemoglobin (HbA1C) reduced to 6%. This is a measure of how well controlled the blood sugar was over the last 3months. On further follow-up, 77% of these patients have either recorded complete remission or significant improvement by the 6th year post surgery (Shabbir & Dargan).
Dyslipidemia is an elevated level of bad cholesterol and reduced level of good cholesterol in the blood. This condition results in deposition of fat inside blood vessel walls with subsequent narrowing and reduction of blood flow to end organs; one of the causes of myocardial infarction (heart attack).
Serum lipids that serve as cardiovascular risk factors such as triglycerides, low-density lipoprotein (LDL) cholesterol, declined after bariatric surgery while high-density lipoprotein (HDL) cholesterol that is cardio-protective increased significantly. The changes were superior to what results of lipid-lowering drugs (Benraouane & Litwin, 2011).
This is joint inflammation and destruction of joint cartilage and architecture resulting from wear and tear aggravated by excess weight on the weight-bearing joints. The results are a pain, joint deformity and reduced range of movement across the joint. Those with BMI>30kg/m2 are 4times likely to have osteoarthritis of the knee than people of healthy weight (Edwards et al., 2012).
A study looked into changes in pain and physical function following bariatric surgery. The average BMI of the participants was 45.9kg/m2 while the average age was 47years. The participants either underwent a Lap band or Roux-en-Y gastric bypass. After one year of surgery, 57.6% of them recorded significant improvement in body pain, and 76.5% of them had improvement in physical function. More than half of the participants were able to walk for a more extended period than before surgery.
Those who had severe knee and hip pain/disability also had significant improvement. About three-fourths experienced growth in the knee and hip pain. These improvements in the knee and hip pain/function, as well as increased in walk time, were maintained at three years post-surgery (King et al., 2016).
Another study examined the effect of bariatric surgery on the symptoms of knee osteoarthritis. The average BMI of the participants was higher than 35kg/m2, and they all had clinical and radiographic evidence of knee osteoarthritis before surgery. Their symptoms were assessed at 6months and 12months post-surgery, and all of them had significant improvement in symptoms as compared to their conditions before bariatric surgery (Edwards et al., 2012).
Infertility and irregular menses
The growth and development of eggs in females and their entire reproductive cycle are driven by various hormones. These hormones are steroid hormones (i.e., derivatives of cholesterol). Hormonal imbalance, therefore, occurs in obese individuals leading to irregular menses and inability to achieve pregnancy. Another problem that may prevent pregnancy in overweight females is a condition known as a polycystic ovarian syndrome (PCOS).
After bariatric surgery, a restoration of the regular menstrual cycle was reported in 71.4% of obese patients who had menstrual irregularities before surgery. The chance of ovulation also increases with the degree of weight loss (Teitelman, Grotegut, Williams, & Lewis, 2006).
In a review of 13 studies involving a total of 2130 obese female patients, 45.6% of them had PCOS before surgery. This figure reduced to 6.8% 12months after operation in addition to the reduction in menstrual irregularities (Skubleny et al., 2015).
Improvement in fertility has been recorded in infertile obese women after undergoing bariatric surgery. Sixty-nine (69) women were able to get pregnant out of 110 infertile overweight women who had bariatric surgery or intragastric balloon device placement. Not only did they get pregnant, but pregnancies also progressed to term with live births. The degree of weight loss and reduction in BMI were found to be suitable predictors of pregnancy after bariatric surgery (Musella et al., 2012).
Obstructive sleep apnea
While sleeping at night, obese individuals often stop breathing temporarily. This serial cessation of breathing interrupts sleep and makes them feel drowsy and sleepy during the day. They also snore while asleep. Obstructive sleep apnea is a risk factor for hypertension and depression. In severe cases, the patient may find it challenging to sleep necessitating the use of continuous positive airway pressure (CPAP) machine.
Obstructive sleep apnea resolved in 46% of patients who had bariatric surgery. There was also an improvement in oxygen saturation (Valencia-Flores et al., 2004).
Obese people are prone to develop stones in the gallbladder. This often leads to irritation and inflammation of the gallbladder with pain in the right upper abdomen, nausea, vomiting, and fever. The stone may also block the flow of bile into the small intestine resulting in difficult digestion of fatty foods and reduced absorption of fat-soluble vitamins such as vitamins A, D, E, and K. The gallbladder is usually removed during gastric bypass surgery as a therapeutic measure in patients with gallstone or as a prophylactic measure to prevent the formation of gallstone after surgery.
Accumulation of fat in the liver, a condition known as the fatty liver is commonly seen in obese people. This condition may progress to fatty liver disease and further damages the liver with the destruction of liver architecture (liver cirrhosis). Cirrhosis may continue to transform into malignancy at a later stage. Improvement in fatty liver disease after bariatric surgery has been reported by many studies (Nostedt et al., 2016).
Gastro-esophageal reflux disease (GERD)
This is not uncommon in patients who are obese. The acidic stomach contents regurgitate into the lower part of the esophagus leading to inflammation. Those who have a defect in the esophageal hiatus (a hole in the diaphragm that affords passage to the esophagus) may have the abdominal contents such as stomach herniates into the chest. The result of this is heartburn, nausea, and vomiting, cough, difficulty with swallowing, etc.
Although gastric sleeve surgery has been associated with mixed effects on GERD (improvement, exacerbation or even newly onset symptoms), the condition has been reported to improve significantly after gastric bypass surgery (Rrezza et al., 2002).
Obese people suffer from psychological issues partly due to discrimination and stigmatization from people who are of healthy weight, or from low self-esteem due to unacceptable body image. Discrimination and stigmatization may also make obese people end up with low pay jobs. They may, therefore, be seen to have symptoms of depression or those of anxiety.
After bariatric surgery, the weight loss associated with a reversal in comorbidities often result in satisfaction with body image, regaining of self-esteem. Discrimination and stigmatization reduce, the patient has a sense of control over his life. All these have been found to contribute positively to the mental health of patients after bariatric surgery. Nevertheless, unrealistic expectations of dramatic life changes after bariatric surgery may be counterproductive.
A study from Masters et al. revealed that overweight and obesity were responsible for 18.2% of deaths among U.S. adults (both blacks and whites and both genders) over a period of two decades (1986-2006) (Masters et al., 2013). Adams et al. studied 500,000 people between the ages of 50-71 years in the U.S. Overweight individuals (BMI 25-29.9kg/m2) have a mortality rate that is 20-40% higher than in healthy-weight individuals of the same age. This rate of death tripled in the obese (BMI ≥30kg/m2) individuals (Adams, Schatzkin, & Harris, 2006).
In comparison with their healthy-weight counterparts, morbidly obese (grade III obesity) men who are 25years or more have a reduction in life expectancy of about 22%. This translates to death 12 years earlier than the healthy-weight counterparts (Fontaine, 2003). With weight loss and reversal of comorbid conditions, an obese individual can return significantly reduce his risk of death and prolong his survival.
In conclusion, obesity is a significant health problem due to other disease conditions associated with it. Bariatric surgeries are currently most effective solutions to obesity. Though the most visible outcome is weight loss, many other health benefits are seen concerning the degree of weight loss while some are even independent of the degree of weight loss. Thus, bariatric surgery should be seen as a gateway to healthy living and prolonged survival for the obese people.
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