6.0.0.0 METABOL­IC SURGERY

6.1.0.0 Rec­om­men­da­tions

Rec­om­men­da­tions

8.11 Metabol­ic surgery should be rec­om­mend­ed as an op­tion to treat type 2 di­a­betes in ap­pro­pri­ate sur­gi­cal can­di­dates with BMI ≥40 kg/m2 (BMI ≥37.5 kg/m2 in Asian Amer­i­cans) and in adults with BMI 35.0–39.9 kg/m2 (32.5–37.4 kg/m2 in Asian Amer­i­cans) who do not achieve durable weight loss and im­provement in co­mor­bidities (in­clud­ing hy­per­glycemia) with rea­son­able nonsur­gi­cal meth­ods. A

8.12 Metabol­ic surgery may be con­sid­ered as an op­tion for adults with type 2 di­a­betes and BMI 30.0– 34.9 kg/m2 (27.5–32.4 kg/m2 in Asian Amer­i­cans) who do not achieve durable weight loss and im­provement in co­mor­bidities (in­clud­ing hy­per­glycemia) with rea­son­able nonsur­gi­cal meth­ods. A

8.13 Metabol­ic surgery should be per­formed in high-‍vol­ume cen­ters with mul­ti­dis­ci­plinary teams that un­der­stand and are ex­pe­ri­enced in the man­age­ment of di­a­betes and gas­troin­testi­nal surgery. C

8.14 Long-‍term lifestyle sup­port and rou­tine mon­i­tor­ing of mi­cronu­tri­ent and nu­tri­tion­al sta­tus must be pro­vided to pa­tients after surgery, ac­cord­ing to guide­lines for post­op­er­a­tive man­age­ment of metabol­ic surgery by na­tion­al and interna­tion­al pro­fes­sion­al so­ci­eties. C

8.15 Peo­ple pre­senting for metabol­ic surgery should re­ceive a com­pre­hen­sive readi­ness and men­tal health as­sessment. B

8.16 Peo­ple who un­der­go metabol­ic surgery should be eval­u­ated to as­sess the need for on­go­ing men­tal health ser­vices to help them ad­just to med­i­cal and psy­choso­cial changes after surgery. C

Sev­er­al gas­troin­testi­nal (GI) op­er­a­tions in­clud­ing par­tial gas­trec­tomies and bariatric pro­ce­dures (35) pro­mote dra­mat­ic and durable weight loss and im­provement of type 2 di­a­betes in many pa­tients. Given the mag­ni­tude and ra­pid­i­ty of the ef­fect of GI surgery on hy­per­glycemia and experimen­tal ev­i­dence that re­ar­range­ments of GI anato­my sim­i­lar to those in some metabol­ic pro­ce­dures di­rect­ly af­fect glu­cose home­osta­sis (36), GI in­ter­ven­tions have been sug­gest­ed as treat­ments for type 2 di­a­betes, and in that con­text they are termed “metabol­ic surgery.”

A sub­stan­tial body of ev­i­dence has now been ac­cu­mu­lat­ed, in­clud­ing data from nu­mer­ous ran­dom­ized con­trolled (non­blind­ed) clin­i­cal tri­als, demon­strat­ing that metabol­ic surgery achieves su­pe­ri­or glycemic con­trol and re­duc­tion of car­dio­vas­cu­lar risk fac­tors in pa­tients with type 2 di­a­betes and obe­si­ty com­pared with var­i­ous lifestyle/med­i­cal in­ter­ven­tions (17). Im­prove­ments in mi­crovas­cu­lar com­pli­ca­tions of di­a­betes, car­dio­vas­cu­lar dis­ease, and can­cer have been ob­served only in nonran­dom­ized ob­ser­va­tion­al stud­ies (44-53,). Co­hort stud­ies at­tempt­ing to match sur­gi­cal and nonsur­gi­cal sub­jects sug­gest that the pro­ce­dure may re­duce longer-‍term mor­tal­i­ty (45).

On the basis of this mount­ing ev­i­dence, sev­er­al or­ga­ni­za­tions and gov­ern­ment agen­cies have rec­om­mend­ed ex­pan­ding the in­di­ca­tions for metabol­ic surgery to in­clude pa­tients with type 2 di­a­betes who do not achieve durable weight loss and im­provement in co­mor­bidities (in­clud­ing hy­per­glycemia) with rea­son­able nonsur­gi­cal meth­ods at BMIs as low as 30 kg/m2 (27.5 kg/m2 for Asian Amer­i­cans) (54-61,). Please refer to “Metabol­ic Surgery in the Treat­ment Al­go­rithm for Type 2 Di­a­betes: A Joint State­ment by In­terna­tion­al Di­a­betes Or­ga­ni­za­tions” for a thor­ough re­view (17).

Ran­dom­ized con­trolled tri­als have doc­u­ment­ed di­a­betes re­mis­sion dur­ing post­op­er­a­tive fol­low-‍up rang­ing from 1 to 5 years in 30%–63% of pa­tients with Roux-‍en-‍Y gas­tric by­pass (RYGB), which gen­er­ally leads to greater de­grees and lengths of re­mis­sion com­pared with other bariatric surg­eries (17,62). Avail­able data sug­gest an ero­sion of di­a­betes re­mis­sion over time (63): 35%–50% or more of pa­tients who ini­tially achieve re­mis­sion of di­a­betes even­tu­al­ly ex­pe­ri­ence re­cur­rence. How­ev­er, the me­di­an dis­ease-‍free pe­ri­od among such in­di­vid­u­als fol­low­ing RYGB is 8.3 years (64,65). With or with­out di­a­betes re­lapse, the ma­jor­i­ty of pa­tients who un­der­go surgery main­tain sub­stan­tial im­provement of glycemic con­trol from base­line for at least 5 (66,67) to 15 (45,46,65,68–70) years.

Ex­ceed­ing­ly few presur­gi­cal pre­dic­tors of suc­cess have been iden­tified, but younger age, short­er du­ra­tion of di­a­betes (e.g., <8 years) (71), nonuse of in­sulin, main­te­nance of weight loss, and bet­ter glycemic con­trol are con­sis­tently as­so­ci­at­ed with high­er rates of di­a­betes re­mis­sion and/‍or lower risk of weight re­gain (45,69,71,72). Greater base­line vis­cer­al fat area may also help to pre­dict bet­ter post­op­er­a­tive out­comes, es­pe­cial­ly among Asian Amer­i­can pa­tients with type 2 di­a­betes, who typ­i­cal­ly have more vis­cer­al fat com­pared with Cau­casians with di­a­betes of the same BMI (73).

Be­yond im­prov­ing glycemia, metabol­ic surgery has been shown to con­fer ad­di­tion­al health benefits in ran­dom­ized con­trolled tri­als, in­clud­ing sub­stan­tial re­duc­tions in car­dio­vas­cu­lar dis­ease risk fac­tors (17), re­duc­tions in in­ci­dence of mi­crovas­cu­lar dis­ease (74), and en­hance­ments in qual­i­ty of life (66,71,75).

Al­though metabol­ic surgery has been shown to im­prove the metabol­ic profiles of pa­tients with type 1 di­a­betes and mor­bid obe­si­ty, es­tab­lish­ing the role of metabol­ic surgery in such pa­tients will re­quire larg­er and longer stud­ies (76).

Metabol­ic surgery is more ex­pen­sive than nonsur­gi­cal man­age­ment strate­gies, but ret­ro­spec­tive anal­y­ses and mod­el­ing stud­ies sug­gest that metabol­ic surgery may be cost-‍ef­fec­tive or even cost-‍sav­ing for pa­tients with type 2 di­a­betes. How­ev­er, re­sults are large­ly de­pen­dent on as­sump­tions about the long-‍term ef­fec­tiveness and safe­ty of the pro­ce­dures (77,78).