Metabolic hormones mediate cognition

Recent biochemical and behavioural evidence indicates that metabolic hormones not only regulate energy intake and nutrient content, but also modulate plasticity and cognition in the central nervous system. Disruptions in metabolic hormone signalling may provide a link between metabolic syndromes like obesity and diabetes, and cognitive impairment. For example, altered metabolic homeostasis in obesity is a strong determinant of the severity of age-related cognitive decline and neurodegenerative disease. Here we review the evidence that eating behaviours and metabolic hormones-particularly ghrelin, leptin, and insulin-are key players in the delicate regulation of neural plasticity and cognition. Caloric restriction and antidiabetic therapies, both of which affect metabolic hormone levels can restore metabolic homeostasis and enhance cognitive function. Thus, metabolic hormone pathways provide a promising target for the treatment of cognitive decline.

Glucose-lowering drugs or strategies, atherosclerotic cardiovascular events, and heart failure in people with or at risk of type 2 diabetes: an updated systematic review and meta-analysis of randomised cardiovascular outcome trials

BACKGROUND

In our 2015 systematic review and meta-analysis of cardiovascular outcome trials for glucose-lowering drugs or strategies in people with or at risk of type 2 diabetes, we reported a modest reduction in atherosclerotic cardiovascular events and an increased risk of heart failure, but with heterogeneous effects by drug or intervention type. In view of the completion of many large cardiovascular outcome trials since our previous analysis, including trials of novel drugs that have shown beneficial effects on cardiovascular outcomes, we aimed to update our analysis to incorporate these findings.

METHODS

We did an updated systematic review and meta-analysis of large cardiovascular outcome trials of glucose-lowering drugs or strategies in people with or at risk of type 2 diabetes. We searched Ovid MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials databases for reports of trials published from Nov 15, 2013 to Nov 20, 2019. We included randomised controlled trials with a minimum of 1000 adults (aged ≥19 years) with or at risk of type 2 diabetes, with major adverse cardiovascular events (MACE) as an outcome, and with follow-up of at least 12 months. We excluded trials with patients enrolled with an acute cardiovascular event. The main outcomes of interest were MACE (generally defined as a composite of cardiovascular death, myocardial infarction, or stroke) and heart failure. We calculated pooled risk ratios (RRs) and 95% CIs with inverse-variance random-effects models, did meta-regression to analyse treatment effects per difference in bodyweight achieved, and explored results stratified by baseline subgroups.

FINDINGS

Our updated search yielded 30 eligible trials (n=225 305). The mean age of participants was 63·0 years (SD 8·4) and mean duration of diabetes was 9·4 years (6·6). After a mean follow-up of 3·8 years (1·8), 23 016 (10·2%) participants had MACE and 8169 (3·6%) had a heart failure event. Glucose-lowering drugs or strategies lowered the risk of MACE compared with standard care or placebo (RR 0·92, 95% CI 0·89-0·95, p<0·0001), with no overall effect on the risk of heart failure (0·98, 0·90-1·08, p=0·71). However, across drug classes or strategies, the magnitude and directionality of RR for heart failure varied (p_interaction<0·0001), with meta-regression showing that a decrease in bodyweight of 1 kg was associated with a 5·9% (3·9-8·0) relative decrease in the risk of heart failure (p<0·0001). Among trials that assessed drug classes or strategies associated with weight loss (intensive lifestyle changes, GLP-1 receptor agonists, or SGLT2 inhibitors), the risk reduction for MACE was consistent among participants with (0·87, 0·83-0·92) and without (0·92, 0·83-1·02) established cardiovascular disease at baseline (p_interaction=0·33). For heart failure, the RR for drug classes or strategies associated with weight loss was consistent among participants with (0·80, 0·73-0·89) and without (0·84, 0·74-0·95) cardiovascular disease at baseline (p_interaction=0·63).

INTERPRETATION

Glucose-lowering drugs or strategies overall reduced the risk of fatal and non-fatal atherosclerotic events. The effect on heart failure was neutral overall but varied substantially by intervention type, with interventions associated with weight loss showing a beneficial effect. The cardiovascular and heart failure benefits of interventions associated with weight loss might extend to patients without established cardiovascular disease.

FUNDING

None.

4113Glucose lowering drugs or strategies, major adverse cardiovascular events and heart failure outcomes, and association with weight loss - meta-analysis of large cardiovascular outcome trials

Background

Glucose lowering drugs or strategies (GLDS) have varied effects on major adverse cardiovascular events (MACE) and heart failure (HF) in cardiovascular outcomes trials. Mechanisms driving cardiovascular risk reduction remain elusive.

Methods

We searched MEDLINE, PubMed, and meeting abstracts up to 11/21/2018 for large GLDS cardiovascular outcome trials (CVOTs) in patients with or at risk for type 2 diabetes. Primary endpoints of MACE and HF were evaluated with random effects risk ratios (RR) and explored by baseline CVD subgroups and meta-regression by weight change across treatment arms.

Results

In 27 GLDS CVOTs, a total 207,820 patients, median age 63 years, 64% male, 64% CVD and 11% with prior HF were studied over a mean 3.8 years with 20,118 (10%) patients having MACE and 7,212 (4%) a HF event. Compared with standard care, GLDS overall lowered MACE (RR 0.92, P<0.ehz745.01171) but not HF (RR 1.01, P=0.91). Across GLDS, the magnitude and directionality varied modestly for MACE RR (P-int=0.07) but markedly for HF (P-int<0.ehz745.01171). Meta-regression showed a change in HF RR by 6% (95% CI 3%-9%) per 1 kg weight gain/loss between treatment arms (P=0.0006; Figure). In 9 trials of GLDS that achieved marked weight loss (lifestyle, GLP1 agonists, SGLT2 inhibitors), MACE benefit was confined to patients with baseline CVD (RR 0.89 [0.84–0.95] versus without (RR 1.02 [0.91–1.15]; P-int=0.01) with consistent HF effect (RR 0.80 [0.72–0.88] vs RR 0.76 [0.56–1.03]; P-int=0.74).

Heart Failure Risk and Changes in Weight

Conclusion

HF outcomes were improved with GLDS that lower weight. Among diabetes GLDS that lower weight, there was a robust risk reduction in atherothrombotic and heart failure events, with the MACE benefit confined to patients with established CVD.

Acknowledgement/Funding

Heart and Stroke Foundation