obesity is one of the most serious and urgent public health problems in western societies because of its metabolic and cardiovascular complications that negatively impact on life expectancy . equally alarming
is the increase of morbid obesity ( bmi  40  kg / m ) that quadrupled over the last decade , whereas extreme obesity ( bmi > 50  kg / m ) increased fivefold .  
bariatric surgery , also known as metabolic surgery , has emerged as a highly effective and long - lasting treatment in patients with morbid obesity and in those with bmi  35 
kg / m in the presence of type 2 diabetes ( t2 dm ) and other comorbidities .
there is extensive evidence that bariatric procedures , including biliopancreatic diversion ( bpd ) , gastric bypass ( gbp ) , and gastric banding , can successfully control most of the obesity - related comorbidities , such as hypertension , dyslipidemia , and t2 dm .
the rate of success is higher with the predominantly malabsorptive and mixed malabsorptive - restrictive procedures than purely restrictive operations .  
laparoscopic sleeve gastrectomy ( lsg ) is emerging as a new promising therapy for the treatment of morbid obesity .
this procedure , originally conceived as a first stage for achieving weight loss in superobese patients before performing gbp or bpd , has revealed to be effective on its own and a potential competitor with these operations . in fact , lsg has the advantage to be less invasive than gbp and bdp , and not inferior in terms of sustained weight loss , as demonstrated in some preliminary studies .
few studies have examined the effects of lsg on glucose control and comorbidities in obese t2 dm patients , and limited information is available on the long - term efficacy of this procedure [ 79 ] .
therefore , in the present study we assessed the medium - term ( 915 months ) effects of lsg on body weight and glucose homeostasis in severely obese t2 dm subjects not adequately controlled with medical therapy .
in addition , we evaluated the impact of lsg on other pathological conditions linked to obesity , that is , hypertension and dyslipidemia .
the study was conducted at the department of surgery , s. giovanni bosco hospital , naples and at the department of clinical and experimental medicine , federico ii university , naples .  
a total of 25 obese t2 dm subjects ( 10  m/15  f , age 45  9 years , bmi 48  8  kg / m , m  sd ) underwent lsg surgery .
all patients were examined by a multidisciplinary and integrated medical team consisting of a diabetologist , a bariatric surgeon , a psychiatrist , and a dietician .  
the inclusion criteria were as follows : age 3565 years , bmi  35  kg / m , duration of diabetes > 1 year .
exclusion criteria were age < 35 years or > 65 years , bmi < 35  kg / m , fasting c - peptide level < 1  ng / ml , endocrine obesity , a history of medical problems such as mental impairment , drug or alcohol addiction , recent major vascular event   and excessive surgical risks due to debilitating diseases that considerably impair life expectancy according to perioperative bariatric guidelines .  
all patients underwent complete evaluation before and at 3 and 915 months after surgery including anthropometric / clinical parameters and laboratory tests .
insulin - resistance was evaluated by the homeostasis model assessment of insulin resistance ( homa - ir ) index using a standard formula : fasting insulin ( u / l )  fasting glucose ( mmol / l ) divided by 22.5 .  
the first step consists in opening the gastrocolic ligament attached to the stomach , usually starting 1012  cm from the pylorus toward the lower pole of the spleen .
then the gastric greater curvature is freed up to the cardiooesophageal junction close to stomach sparing the gastroepiploic vessels .
meticulous dissection is performed at the angle of his with full mobilization of the gastric fundus .
the mobilization of the stomach continues dissecting the greater gastric curve toward the antrum up to 35  cm from the pylorus . at this time
a 40-fr orogastric tube is inserted direct toward the pylorus , proximal to the lesser curvature of the stomach .
then , the stomach is resected with linear staplers parallel to orogastric tube along the lesser curve starting 35  cm far from pylorus .
the orogastric bougie is replaced by a nasogastric tube that is positioned in the distal stomach to perform a methylene blue test .
the transection line is inspected to search blue positivity . in case of negative test , the resected stomach is removed by left midabdominal trocar usually without prolonging incision .
remission of t2 dm was defined as fasting plasma glucose below 126  mg / dl and hba1c below 6.5% in the absence of hypoglycemic treatment .
remission of hypertension was defined as blood pressure below 140/90  mmhg in the absence of antihypertensive treatment ; remission of dyslipidemia was defined as fasting plasma ldl - cholesterol below 100  mg / dl and/or fasting plasma triglycerides below 190  mg / dl in the absence of pharmacological therapy .
anova with repeated measures was used to detect changes over time of the anthropometric and biochemical variables .
paired student 's t - tests were used to compare data before and after surgery .
all statistical analyses were performed using spss version 13.0 ( spss inc . , chicago , il ) .
all patients had a duration of t2 dm > 1 year ( 3  2 years ) , and most of them ( 68% ) were in poor glycaemic control , as evidenced by hba1c > 7% .
two patients were on diet , twenty - one patients took oral hypoglycemic agents , and two were on combined therapy ( oral agents plus insulin ) .
twenty - one ( 84% ) patients were on antihypertensive therapy , and fourteen ( 56% ) patients received hypolipidemic drugs .  
mean bmi decreased from the basal value of 48  8  kg / m to 39  8  kg / m ( p < .001 ) at 3 months and to 34  6  kg / m ( p < .001 ) 915 months after surgery .
percent excess weight was 81  42% at 3 months and 61  33% ) at 915 months compared to basal value ( 122  39% ; p < .001 for both ) . fasting
plasma glucose significantly decreased to 87  19  mg / dl 3 months after lsg and remained within the normal range at 915 months in all patients but one .
mean hba1c reached 5.9  0.6% at 3 months and remained unchanged at 915 months ( 5.8  0.7% ) ( p < .03 ) .
fasting plasma insulin declined   significantly by 6887% following the intervention ( p < .005 ) . as a consequence homa - ir dramatically decreased by 86% ( p < .008 ) 3 months after surgery and remained stable thereafter ( 91% , p < .04 ) .  
following surgery , all patients discontinued their hypoglycemic medications , and a full remission of t2 dm was achieved in 24 out of 25 patients .
eighteen patients discontinued antihypertensive drugs , and 12 patients discontinued hypolipidemic drugs at 3 months .
a major perioperative complication occurred in one patient who was admitted to intensive care unit for acute renal failure due to severe dehydration .
our study shows that lsg is effective in producing a significant and sustained weight loss and improving glucose homeostasis in severely obese t2 dm patients .
in fact , after 915 months from surgery all patients but one achieved a good glycemic control with discontinuation of hypoglycaemic treatment .
this finding is in line with previous studies demonstrating that diabetes resolution occurs in 6680% of patients undergoing lsg [ 711 ] .  
although the mechanisms underlying t2 dm remission following lsg has yet to be fully determined , some human studies have reported favourable changes in insulin sensitivity [ 12 , 13 ] . in our patients , insulin resistance evaluated by homa index
decreased by 80% thus confirming previous data by abbatini et al . who demonstrated a near - normalization of insulin resistance measured by euglycemic clamp in patients treated with lsg .
the improvement in insulin sensitivity is primarily due to weight loss , reduction in inflammatory mediators , and decreased calorie intake although the contribution of weight independent mechanisms seems very likely .
potential mechanisms include enhanced stimulation of gastrointestinal hormones secondary to rearrangement of gastrointestinal anatomy . for malabsorptive / mixed procedures ( rygb and bdp )
relevant and rapid changes in the enterohormonal axis have been demonstrated , consisting of complete recovery of meal - stimulated response of glp-1 and gip .
these modifications , evident already a few days after surgery , may explain the rapid improvement of glucose homeostasis before substantial weight loss has occurred [ 14 , 15 ] .
the long - term evaluation of these patients has also shown that the recovery of incretin response is maintained over time , probably contributing to the recovery of beta - cell function .
regarding lsg , recent studies have shown that this procedure is associated with a marked reduction of ghrelin secretion , an orexigenic peptide produced by the gastric fundus involved in mealtime hunger regulation .
ghrelin is also known to exert several diabetogenic effects ( increase in growth hormone , cortisol , and epinephrine ) ; therefore its suppression could contribute to improved glucose homeostasis .
interestingly , we observed an increased meal - stimulated glp-1 and gip response in our patients at 3 weeks postoperatively , which may have concurred to amelioration of glucose metabolism ( unpublished observations ) .  
none of the patients studied presented any sign of nutritional deficiencies at 915-month follow - up , confirming that lsg is a safe procedure in terms of nutritional status at odds with malabsorptive or mixed surgical procedures which often lead to multiple nutritional consequences due to the bypass of duodenum and jejunum .   in conclusion , lsg induces stable weight loss and resolution of t2 dm diabetes and other obesity - associated comorbidities in a large majority of patients .
controlled long - term comparisons between different bariatric interventions are needed to establish the optimal procedure in relation to patients ' characteristics .
 this study was undertaken to assess medium - term effects of laparoscopic sleeve gastrectomy ( lsg ) on body weight and glucose homeostasis in severely obese type 2 diabetic ( t2 dm ) subjects . 
 twenty - five obese t2 dm subjects ( 10  m/15  f , age 45  9 years , bmi 48  8  kg / m2 , m  sd ) underwent evaluation of anthropometric / clinical parameters and glucose homeostasis before , 3 and 915 months after lsg . mean bmi decreased from 48  8  kg / m2 to 40  9  kg / m2 ( p < .001 ) at 3 months and 34  6  kg / m2 ( p < 
 .001 ) at 915 months after surgery . remission of t2 dm ( fasting plasma glucose < 126  mg / dl and hba1c < 6.5% in the absence of hypoglycemic treatment ) occurred in all patients but one . there was a remarkable reduction in the percentage of patients requiring antihypertensive and hypolipidemic drugs . 
 our study shows that lsg is effective in producing a significant and sustained weight loss and improving glucose homeostasis in severely obese t2 dm patients . 
1. Introduction
2. Methods
3. Results
4. Discussion