Plasma concentration of proneurotensin and prediction of cause-specific mortality in a middle aged cohort during long-term follow-up

Purpose

To examine the prediction of proneurotensin (Pro-NT) on total and cause-specific mortality in a middle-aged cohort.

Methods

In the population-based middle-aged cohort (n=4632 participants, mean age 57 years) of the Malmo Diet and Cancer (MDC) study, Pro-NT was assessed and total- as well as cause-specific mortality were studied. Main cause of death were based on the International Classification of Diseases (ICD). Assessments were done using Cox proportional hazards models adjusted for age and sex.

Results

During a mean follow-up of 20±3 years, 950 men and 956 women died. There was a significantly increased risk of total mortality in subjects belonging to quartile 4 of Pro-NT (Pro-NT ≥149 pmol/L) compared with quartiles 1–3 (Pro-NT <149 pmol/L), hazard ratio (HR) of 1.29 (95% confidence interval [CI] 1.17–1.42; P<0.001) after adjustment for age and sex. No significant interaction was observed between Pro-NT and gender on total mortality. Individuals within quartile 4 vs. quartiles 1–3 had a HR of 1.41 (95% CI 1.18–1.68; P<0.001) for death due to cardiovascular diseases (n=595/4632), 2.53 (95% CI 1.37–4.67; P=0.003) due to digestive tract diseases (n=42/4632), 1.62 (95% CI 1.04–2.52; P=0.032) due to mental and behavioural diseases (n=90/4632), and 1.91 (95% CI 1.15–3.19; P=0.013) due to unspecific causes of death (n=64/4632). No significant relationships between Pro-NT and deaths due to cancer, infections, neurological or other causes were observed. Adjustments for cardiovascular risk factors only marginally changed these results.

Conclusions

Pro-NT is a predictor of total mortality and the increased risk is driven by deaths due to cardiovascular- digestive tract- mental and behavioural diseases, as well as deaths attributed to unspecific causes.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Knut and Alice Wallenberg Foundationthe Swedish Heart and Lung Foundation.

The association between plasma proneurotensin and glucose regulation is modified by country of birth

The prevalence of type 2 diabetes (T2D) has increased dramatically in Middle Eastern populations that represent the largest non-European immigrant group in Sweden today. As proneurotensin predicts T2D, the aim of this study was to investigate differences in proneurotensin levels across populations of Middle Eastern and Caucasian origin and to study its associations with indices of glucose regulation. Participants in the age 30 to 75 years, living in Malmö, Sweden, and born in Iraq or Sweden, were recruited from the census register. Anthropometrics and fasting samples were collected and oral glucose tolerance tests conducted assessing insulin secretion (DIo) as well as insulin sensitivity (ISI). A total of 2155 individuals participated in the study, 1398 were Iraqi-born and 757 were Swedish-born participants. Higher fasting proneurotensin levels were observed in Iraqi- compared to Swedish-born participants (137.5 vs. 119.8 pmol/L; p < 0.001) data adjusted for age, sex and body mass index. In Iraqi participants only, plasma proneurotensin was associated with impaired glucose regulation assessed as ISI, DIo and HbA1c, and significant interactions between country of birth and proneurotensin were observed (Pinteraction ISI = 0.048; Pinteraction DIo = 0.014; PinteractionHbA1c = 0.029). We report higher levels of proneurotensin in the general Middle Eastern population. The finding that Middle Eastern origin modifies the relationship of proneurotensin with indices of glucose regulation suggests that proneurotensin may be a stronger determinant of T2D in Middle Eastern as compared to Caucasian populations. These findings may explain part of the excess T2D risk in the Middle Eastern population but needs to be explored further.

Fasting leptin and glucose in normal weight, over weight and obese men and women diabetes patients with and without clinical depression

A large number of diabetes patients suffer from major depression and are at high risk of mortality. In view of a role of leptin in diabetes, depression and energy homeostasis, the present study concerns circulating levels of leptin in different BMI groups of un-depressed and depressed diabetes patients. Six hundred thirty male and female patients with a primary diagnosis of diabetes were grouped according to BMI and with or without clinical symptoms of depression. Age matched healthy, normal weight male and female volunteers without clinical symptoms of depression or diabetes were taken as controls. Blood samples were obtained after an overnight fast of 12 h. Serum was stored for the determination of leptin and glucose. We found that there were more female than male diabetes patients with comorbid depression. Fasting leptin was higher in normal weight non-diabetes women than men; but comparable in normal weight men and women diabetes patients. Fasting glucose levels were higher in diabetes than non diabetes groups; values were comparable in men and women. Depression was associated with a decrease and increase in leptin respectively in normal-overweight and obese men and women diabetes patients. Glucose levels were also higher in obese depressed than un-depressed diabetes patients. The results suggested that the female gender is at greater risk to comorbid diabetes with depression. Adipo-insular axis plays an important role in diabetes, associated depression and in the greater risk of the female gender to comorbid diabetes with depression.