The relationship between N-terminal prosomatostatin, all-cause and cardiovascular mortality in patients with type 2 diabetes mellitus (ZODIAC-35)

N-Terminal Prosomatostatin and Risk of Vascular Dementia

BACKGROUND

Increased somatostatin plasma concentration has been found in patients with vascular dementia. However, it is unknown whether or not somatostatin levels may predict dementia development in the general population. To this end, we sought to assess the association of circulating N-terminal prosomatostatin (NT-proSST) with incident dementia among community-dwelling older adults.

METHODS

In the prospective population-based Malmö Preventive Project, 5,347 study participants (mean age: 69 ± 6years; 70% men) provided plasma for the determination of NT-proSST concentration. Of these, 373 participants (7%) were diagnosed with dementia (120 Alzheimer's disease, 83 vascular, 102 mixed, and 68 other aetiology) during a follow-up period of 4.6 ± 1.3 years. The association of NT-proSST with the risk of dementia and its subtypes was studied using multivariable-adjusted Cox regression models controlling for age, gender, body mass index, systolic blood pressure, antihypertensive treatment, smoking, diabetes, lipid levels and prevalent stroke.

RESULTS

Higher levels of NT-proSST were significantly associated with an increased risk of vascular dementia (hazard ratio [HR] per 1 SD: 1.29; 95% CI 1.05-1.59; p = 0.016), whereas no association was observed with Alzheimer's disease (HR per 1 SD: 0.99; 95% CI 0.81-1.20; p = 0.91), all-cause dementia (HR per 1 SD: 1.04; 95% CI 0.94-1.16; p = 0.44), and mixed dementia (HR per 1 SD: 0.98; 95% CI 0.79-1.21; p = 0.84). Levels of NT-proSST above 563 pmol/L (highest quartile) conferred distinctly increased risk of vascular dementia (HR 1.66; 95% CI 1.05-2.63; p = 0.029) compared with lower values.

CONCLUSIONS

Higher levels of circulating N-terminal-prosomatostatin are associated with increased incidence of vascular dementia. Our findings might be of importance for the understanding of dementia development in older adults.

Plasma N-terminal Prosomatostatin and Risk of Incident Cardiovascular Disease and All-Cause Mortality in a Prospective Observational Cohort: the PREVEND Study

BACKGROUND

Somatostatin is a component of the well-known insulin-like growth factor-1/growth hormone (GH) longevity axis. There is observational evidence that increased GH is associated with an increased risk of cardiovascular disease (CVD). We aimed to investigate the potential association of plasma N-terminal fragment prosomatostatin (NT-proSST) with incident CVD and all-cause mortality in apparently healthy adults.

METHODS

We studied 8134 participants without history of CVD (aged 28-75 years; women, 52.6%) from the Prevention of Renal and Vascular End-stage Disease (PREVEND) study in Groningen, the Netherlands. Plasma NT-proSST was measured in baseline samples. Outcomes were incidence of CVD and all-cause mortality.

RESULTS

In cross-sectional analyses, NT-proSST [mean (SD), 384.0 (169.3) pmol/L] was positively associated with male sex and age (both P < 0.001). During a median follow-up of 10.5 (Q1-Q3: 9.9-10.8) years, 708 (8.7%) participants developed CVD and 517 (6.4%) participants died. In univariable analyses, NT-proSST was associated with an increased risk of incident CVD and all-cause mortality (both P < 0.001). In multivariable analyses, these associations were independent of the Framingham risk factors, with hazard ratios (95% CI) per doubling of NT-proSST of 1.17 (1.03-1.34; P = 0.02) for incident CVD and of 1.28 (1.09-1.49; P = 0.002) for all-cause mortality. Addition of NT-proSST to the updated Framingham Risk Score improved reclassification (integrated discrimination improvement (P < 0.001); net reclassification improvement was 2.5% (P = 0.04)).

CONCLUSIONS

Plasma NT-proSST is positively associated with increased risk of future CVD and all-cause mortality, partly independent of traditional CVD risk factors. Further research is needed to address the nature of associations.

N-Terminal Prosomatostatin as a Risk Marker for Cardiovascular Disease and Diabetes in a General Population

CONTEXT

Somatostatin inhibits a range of hormones, including GH, insulin, and glucagon, but little is known about its role in the development of cardiometabolic disease.

OBJECTIVE

The objective of the study was to investigate whether fasting plasma concentration of N-terminal prosomatostatin (NT-proSST) is associated with the development of diabetes, coronary artery disease (CAD), and mortality.

DESIGN, SETTING, AND PARTICIPANTS

NT-proSST was measured in plasma from 5389 fasting participants of the population-based study Malmö Preventive Project, with a mean baseline age of 69.4 ± 6.2 years. Cox proportional hazards models adjusted for traditional cardiovascular risk factors were used to investigate the relationships between baseline NT-proSST and end points, with a mean follow-up of 5.6 ± 1.4 years.

MAIN OUTCOME MEASURES

CAD, diabetes, and mortality were measured.

RESULTS

Overall, NT-proSST (hazard ratio [HR] per SD increment of log transformed NT-proSST) was unrelated to the risk of incident diabetes (220 events; HR 1.05; 95% confidence interval [CI] 0.91-1.20; P = .531) but was related to the risk of incident CAD (370 events; HR 1.17; 95% CI 1.06-1.30; P = .003), all-cause mortality (756 events; HR 1.24; 95% CI 1.15-1.33; P < .001), and cardiovascular mortality (283 events; HR 1.33; 95% CI 1.19-1.43; P < .001). The relationships were not linear, with most of the excess risk observed in subjects with high values of NT-proSST. Subjects in the top vs bottom decile had a severely increased risk of incident CAD (HR 2.41; 95% CI 1.45-4.01; P < .001), all-cause mortality (HR 1.84; 95% CI 1.33-2.53; P < .001), and cardiovascular mortality (HR 2.44; 95% CI 1.39-4.27; P < .001).

CONCLUSION

NT-proSST was significantly and independently associated with the development of CAD, all-cause mortality, and cardiovascular mortality.