Abstract
Background: Hypertension is a leading cause of death worldwide. Population studies have shown that at least two-thirds of hypertension incidence can be attributed directly to overweight and obesity. The underlying mechanisms linking obesity to hypertension are not clear. Various factors have been suggested to play a role in obesity-related hypertension such as the renin-angiotensin-aldosterone system, the sympathetic nervous system, inflammation, insulin resistance, physical inactivity, and abnormal production of adipocytokines. Of all adipocytokines, leptin and adiponectin have received most attention and both hormones are considered as candidate intermediaries between adipose tissue and overweight and obesity-related disorders.
Objectives: To study obesity-related hypertension with special focus on the hormone leptin. As obesity-related hypertension is multifactorial, other biological systems proposed to play a major role were also studied.
Primary hypotheses:
1. leptin is a significant mediator of overweight- and obesity-related hypertension.
2. by investigating several biological systems involved in blood pressure regulation, it would be possible to identify specific factors which would distinguish obese normotensive men from obese hypertensives men.
Methods: The following study designs were used: large-scale epidemiological studies using cross-sectional and prospective data from The Copenhagen City Heart Study (CCHS) and a detailed descriptive cross-sectional study of 130 males. The CCHS is a prospective cardiovascular population-based study initiated in 1976. The cross-sectional study involved 103 obese males with and without hypertension and 27 lean normotensive males. The study subjects underwent various laboratory and clinical tests focusing on the key regulatory mechanisms proposed to be involved in overweight- and obesity-related hypertension
Results: The principal findings of this PhD study were that leptin may be a mediator of hypertension in obese physically inactive subjects. Further, it was found that abnormal regulation of the renin-angiotensin-aldosterone system and increased activity in the sympathetic nervous system distinguished obese normotensive men from obese hypertensive men. No evidence was found for major roles of adiponectin, inflammation, and glucose and insulin metabolism in obesity-related hypertension
Conclusion: Of the various factors proposed to be involved in obesity-related hypertension, we found evidence that leptin, the renin-angiotensin-aldosterone system, and the sympathetic nervous system may play major roles in obesity-related hypertension.
Objectives: To study obesity-related hypertension with special focus on the hormone leptin. As obesity-related hypertension is multifactorial, other biological systems proposed to play a major role were also studied.
Primary hypotheses:
1. leptin is a significant mediator of overweight- and obesity-related hypertension.
2. by investigating several biological systems involved in blood pressure regulation, it would be possible to identify specific factors which would distinguish obese normotensive men from obese hypertensives men.
Methods: The following study designs were used: large-scale epidemiological studies using cross-sectional and prospective data from The Copenhagen City Heart Study (CCHS) and a detailed descriptive cross-sectional study of 130 males. The CCHS is a prospective cardiovascular population-based study initiated in 1976. The cross-sectional study involved 103 obese males with and without hypertension and 27 lean normotensive males. The study subjects underwent various laboratory and clinical tests focusing on the key regulatory mechanisms proposed to be involved in overweight- and obesity-related hypertension
Results: The principal findings of this PhD study were that leptin may be a mediator of hypertension in obese physically inactive subjects. Further, it was found that abnormal regulation of the renin-angiotensin-aldosterone system and increased activity in the sympathetic nervous system distinguished obese normotensive men from obese hypertensive men. No evidence was found for major roles of adiponectin, inflammation, and glucose and insulin metabolism in obesity-related hypertension
Conclusion: Of the various factors proposed to be involved in obesity-related hypertension, we found evidence that leptin, the renin-angiotensin-aldosterone system, and the sympathetic nervous system may play major roles in obesity-related hypertension.
| Originalsprog | Engelsk |
|---|
| Forlag | University of Copenhagen |
|---|---|
| Status | Udgivet - 2011 |