Weight Loss by Low-Calorie Diet Versus Gastric Bypass Surgery in People With Diabetes Results in Divergent Brain Activation Patterns: A Functional MRI Study

Objective: Weight loss achieved with very low-calorie diets (VLCD) can produce remission of Type 2 diabetes (T2D), but weight regain very often occurs with reintroduction of higher calorie intakes. In contrast, bariatric surgery produces clinically significant and durable weight loss, with diabetes remission that translates into reductions in mortality. We hypothesised that in patients living with obesity and pre-diabetes/T2D, longitudinal changes in brain activity in response to food cues as measured using functional MRI would explain this difference. Methods: 16 participants underwent gastric bypass surgery and 19 matched participants undertook a very low calorie (meal replacement) diet for 4 weeks. Brain responses to food cues and resting state functional connectivity was assessed with functional MRI pre- and post-intervention and compared across groups. Results: We show that RYGB results in three divergent brain responses in comparison to VLCD-induced weight loss: (i) VLCD resulted in increased brain reward centre food cue responsiveness whereas in RYGB this was reduced; (ii) VLCD resulted in higher neural activation of cognitive control regions in response to food cues, associated with exercising increased cognitive restraint over eating, whereas RYGB did not; (iii) a homeostatic appetitive system (centred on the hypothalamus) is better engaged following RYGB-induced weight loss than VLCD. Conclusion: Taken together these findings point to divergent brain responses to different methods of weight loss in patients with diabetes, which may explain weight regain after a short-term VLCD in contrast with the enduring weight loss after RYGB.

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Effect of various weight loss interventions on serum NT-proBNP concentration in severe obese subjects without clinical manifest heart failure

Scientific Reports ◽

10.1038/s41598-021-89426-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tim Hollstein ◽

Kristina Schlicht ◽

Laura Krause ◽

Stefanie Hagen ◽

Nathalie Rohmann ◽

...

Keyword(s):

Heart Failure ◽

Weight Loss ◽

Gastric Bypass ◽

Sleeve Gastrectomy ◽

Serum Concentration ◽

Bypass Surgery ◽

Gastric Bypass Surgery ◽

Very Low Calorie Diet ◽

Calorie Diet ◽

The Individual

AbstractObesity is associated with a “natriuretic handicap” indicated by reduced N-terminal fragment of proBNP (NT-proBNP) concentration. While gastric bypass surgery improves the natriuretic handicap, it is presently unclear if sleeve gastrectomy exhibits similar effects. We examined NT-proBNP serum concentration in n = 72 obese participants without heart failure before and 6 months after sleeve gastrectomy (n = 28), gastric bypass surgery (n = 19), and 3-month 800 kcal/day very-low calorie diet (n = 25). A significant weight loss was observed in all intervention groups. Within 6 months, NT-proBNP concentration tended to increase by a median of 44.3 pg/mL in the sleeve gastrectomy group (p = 0.07), while it remained unchanged in the other groups (all p ≥ 0.50). To gain insights into potential effectors, we additionally analyzed NT-proBNP serum concentration in n = 387 individuals with different metabolic phenotypes. Here, higher NT-proBNP levels were associated with lower nutritional fat and protein but not with carbohydrate intake. Of interest, NT-proBNP serum concentrations were inversely correlated with fasting glucose concentration in euglycemic individuals but not in individuals with prediabetes or type 2 diabetes. In conclusion, sleeve gastrectomy tended to increase NT-proBNP levels in obese individuals and might improve the obesity-associated “natriuretic handicap”. Thereby, nutritional fat and protein intake and the individual glucose homeostasis might be metabolic determinants of NT-proBNP serum concentration.

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