PhD project My doctoral project explores the associations between the biomarkers leptin and adiponectin and cardiovascular diseases such as aortic valve stenosis and myocardial infarction. This is done through epidemiological, cohort-based studies on prospectively collected, population-based data with blood samples stored in biobanks, mainly from the Northern Sweden Health and Disease Study (NSHDS).
The overall aim of these doctoral studies is to investigate the impact of the adipokines leptin and adiponectin in cardiovascular morbidity and mortality, as well as in dementia in elderly. Findings may contribute to a better understanding of disease mechanisms, hypothetically leading to improved prediction of prognosis and ultimately possible new treatments of these common public diseases.
Overweight and obesity are growing concerns worldwide. During the last decades, adipose tissue has been discovered as a significant and complex endocrine organ. The signaling factors are adipose tissue derived factors, so called adipokines, which regulate metabolic homeostasis through several pathways. The adipokines have been extensively researched as possible links to several disorders, not least cardiovascular diseases. Increasing fat mass generates higher circulating levels of adipokines, e.g. leptin, except for adiponectin that has an inverse relationship. Adipokines are possible mediators of the increased risk related to the metabolic syndrome and it has been shown that both leptin and adiponectin predict the development of type 2 diabetes.
Elevated leptin levels have also been associated with myocardial infarction, stroke, and aortic stenosis, whereas low levels of adiponectin are associated with increased risk for type 2 diabetes and faster progression of aortic stenosis. Obesity and overweight are also associated with a higher risk of dementia. Here too, the adipokines represent possible mediators between adipose tissue and neurodegenerative and vascular diseases leading to cognitive impairment in elderly.
In 1985, the WHO-initiated project MONICA was initiated in northern Sweden, where data have been collected in eight population-based surveys, conducted between 1986 and 2022, with approximately 13 500 subjects aged 25-74 years. In 1999, previous participants were re-invited for a new survey and ≈ 4000 were re-examined. Blood samples were collected for analyses and were also saved for future analysis. The “Silver-MONICA” Study was conducted between 2016 and 2019. Previous
participants in MONICA with minimum 2 enrolls, the latest by 1999, aged 80 years or more were contacted for an extensive home-based survey. A total of 1595 participants at the second survey in 1999 were estimated to reach 80 years of age or more.
By year 2016 when Silver-MONICA started, 706 out of 1595 were deceased. Out of the reminding 889, 541 (61%) participated in the study. Outcome data such as death and causes of death (DOR), and hospital admissions and related ICD codes (PAR) have been collected from The National Board of Health and Welfare. Finally, the impact of leptin on all-cause and disease-specific (cardiovascular) mortality will be analyzed in data from a population-based study in the nation of Mauritius focusing on
cardiovascular and diabetes type 2 risk factors. Leptin was analyzed in samples from 1987 and 1992, and outcomes (cardiovascular disease and death) were determined in 2007.
