ContextAbout 5% of the US population is morbidly obese. This disease remains
largely refractory to diet and drug therapy, but generally responds well to
bariatric surgery.ObjectiveTo determine the impact of bariatric surgery on weight loss, operative
mortality outcome, and 4 obesity comorbidities (diabetes, hyperlipidemia,
hypertension, and obstructive sleep apnea).Data Sources and Study SelectionElectronic literature search of MEDLINE, Current Contents, and the Cochrane
Library databases plus manual reference checks of all articles on bariatric
surgery published in the English language between 1990 and 2003. Two levels
of screening were used on 2738 citations.Data ExtractionA total of 136 fully extracted studies, which included 91 overlapping
patient populations (kin studies), were included for a total of 22 094
patients. Nineteen percent of the patients were men and 72.6% were women,
with a mean age of 39 years (range, 16-64 years). Sex was not reported for
1537 patients (8%). The baseline mean body mass index for 16 944 patients
was 46.9 (range, 32.3-68.8).Data SynthesisA random effects model was used in the meta-analysis. The mean (95%
confidence interval) percentage of excess weight loss was 61.2% (58.1%-64.4%)
for all patients; 47.5% (40.7%-54.2%) for patients who underwent gastric banding;
61.6% (56.7%-66.5%), gastric bypass; 68.2% (61.5%-74.8%), gastroplasty; and
70.1% (66.3%-73.9%), biliopancreatic diversion or duodenal switch. Operative
mortality (≤30 days) in the extracted studies was 0.1% for the purely restrictive
procedures, 0.5% for gastric bypass, and 1.1% for biliopancreatic diversion
or duodenal switch. Diabetes was completely resolved in 76.8% of patients
and resolved or improved in 86.0%. Hyperlipidemia improved in 70% or more
of patients. Hypertension was resolved in 61.7% of patients and resolved or
improved in 78.5%. Obstructive sleep apnea was resolved in 85.7% of patients
and was resolved or improved in 83.6% of patients.ConclusionsEffective weight loss was achieved in morbidly obese patients after
undergoing bariatric surgery. A substantial majority of patients with diabetes,
hyperlipidemia, hypertension, and obstructive sleep apnea experienced complete
resolution or improvement.

https://jamanetwork.com/journals/jama/articlepdf/199587/JRV40082.pdf

Bariatric surgery: a systematic review and meta-analysis.

Background Weight loss is associated with short-term amelioration and prevention of metabolic and cardiovascular risk, but whether these benefits persist over time is unknown. Methods The prospective, controlled Swedish Obese Subjects Study involved obese subjects who underwent gastric surgery and contemporaneously matched, conventionally treated obese control subjects. We now report follow-up data for subjects (mean age, 48 years; mean body-mass index, 41) who had been enrolled for at least 2 years (4047 subjects) or 10 years (1703 subjects) before the analysis (January 1, 2004). The follow-up rate for laboratory examinations was 86.6 percent at 2 years and 74.5 percent at 10 years. Results After two years, the weight had increased by 0.1 percent in the control group and had decreased by 23.4 percent in the surgery group (P<0.001). After 10 years, the weight had increased by 1.6 percent and decreased by 16.1 percent, respectively (P<0.001). Energy intake was lower and the proportion of physically active ...

Lifestyle, Diabetes, and Cardiovascular Risk Factors 10 Years after Bariatric Surgery

Small synthetic molecules called growth hormone secretagogues (GHSs) stimulate the release of growth hormone (GH) from the pituitary. They act through the GHS-R, a G protein-coupled receptor whose ligand has only been discovered recently. Using a reverse pharmacology paradigm with a stable cell line expressing GHS-R, we purified an endogenous ligand for GHS-R from rat stomach and named it "ghrelin," after a word root ("ghre") in Proto-Indo-European languages meaning "grow." Ghrelin is a peptide hormone in which the third amino acid, usually a serine but in some species a threonine, is modified by a fatty acid; this modification is essential for ghrelin's activity. The discovery of ghrelin indicates that the release of GH from the pituitary might be regulated not only by hypothalamic GH-releasing hormone, but also by ghrelin derived from the stomach. In addition, ghrelin stimulates appetite by acting on the hypothalamic arcuate nucleus, a region known to control food intake. Ghrelin is orexigenic; it is secreted from the stomach and circulates in the bloodstream under fasting conditions, indicating that it transmits a hunger signal from the periphery to the central nervous system. Taking into account all these activities, ghrelin plays important roles for maintaining GH release and energy homeostasis in vertebrates.

https://www.physiology.org/doi/pdf/10.1152/physrev.00012.2004

Ghrelin: Structure and Function

The capacity to adjust food intake in response to changing energy requirements is essential for survival. Recent progress has provided an insight into the molecular, cellular and behavioural mechanisms that link changes of body fat stores to adaptive adjustments of feeding behaviour. The physiological importance of this homeostatic control system is highlighted by the severe obesity that results from dysfunction of any of several of its key components. This new information provides a biological context within which to consider the global obesity epidemic and identifies numerous potential avenues for therapeutic intervention and future research.

Central nervous system control of food intake and body weight

CONTEXT\nAbout 5% of the US population is morbidly obese. This disease remains largely refractory to diet and drug therapy, but generally responds well to bariatric surgery.\n\n\nOBJECTIVE\nTo determine the impact of bariatric surgery on weight loss, operative mortality outcome, and 4 obesity comorbidities (diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea).\n\n\nDATA SOURCES AND STUDY SELECTION\nElectronic literature search of MEDLINE, Current Contents, and the Cochrane Library databases plus manual reference checks of all articles on bariatric surgery published in the English language between 1990 and 2003. Two levels of screening were used on 2738 citations.\n\n\nDATA EXTRACTION\nA total of 136 fully extracted studies, which included 91 overlapping patient populations (kin studies), were included for a total of 22,094 patients. Nineteen percent of the patients were men and 72.6% were women, with a mean age of 39 years (range, 16-64 years). Sex was not reported for 1537 patients (8%). The baseline mean body mass index for 16 944 patients was 46.9 (range, 32.3-68.8).\n\n\nDATA SYNTHESIS\nA random effects model was used in the meta-analysis. The mean (95% confidence interval) percentage of excess weight loss was 61.2% (58.1%-64.4%) for all patients; 47.5% (40.7%-54.2%) for patients who underwent gastric banding; 61.6% (56.7%-66.5%), gastric bypass; 68.2% (61.5%-74.8%), gastroplasty; and 70.1% (66.3%-73.9%), biliopancreatic diversion or duodenal switch. Operative mortality (< or =30 days) in the extracted studies was 0.1% for the purely restrictive procedures, 0.5% for gastric bypass, and 1.1% for biliopancreatic diversion or duodenal switch. Diabetes was completely resolved in 76.8% of patients and resolved or improved in 86.0%. Hyperlipidemia improved in 70% or more of patients. Hypertension was resolved in 61.7% of patients and resolved or improved in 78.5%. Obstructive sleep apnea was resolved in 85.7% of patients and was resolved or improved in 83.6% of patients.\n\n\nCONCLUSIONS\nEffective weight loss was achieved in morbidly obese patients after undergoing bariatric surgery. A substantial majority of patients with diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea experienced complete resolution or improvement.

Bariatric surgery. A systematic review and meta-analysis

Background Weight loss causes changes in appetite and energy expenditure that promote weight regain. Ghrelin is a hormone that increases food intake in rodents and humans. If circulating ghrelin participates in the adaptive response to weight loss, its levels should rise with dieting. Because ghrelin is produced primarily by the stomach, weight loss after gastric bypass surgery may be accompanied by impaired ghrelin secretion. Methods We determined the 24-hour plasma ghrelin profiles, body composition, insulin levels, leptin levels, and insulin sensitivity in 13 obese subjects before and after a six-month dietary program for weight loss. The 24-hour ghrelin profiles were also determined in 5 subjects who had lost weight after gastric bypass and 10 normal-weight controls; 5 of the 13 obese subjects who participated in the dietary program were matched to the subjects in the gastric-bypass group and served as obese controls. Results Plasma ghrelin levels rose sharply shortly before and fell shortly after eve...

Marina K. Ma

Papers

Plasma Ghrelin Levels after Diet-Induced Weight Loss or Gastric Bypass Surgery