Excess abdominal fat leads to excess free fatty acids in the portal vein, increasing fat accumulation in the liver. Fat also accumulates in muscle cells. Insulin resistance develops, with hyperinsulinemia. Glucose metabolism is impaired, and dyslipidemias and hypertension develop. Serum uric acid levels are typically elevated (increasing risk of gout), and a prothrombotic state (with increased levels of fibrinogen and plasminogen activator inhibitor I) and an inflammatory state develop.
Kids who have a family history of heart disease or diabetes are at greater risk for metabolic syndrome. But, as with many things in life, the lifestyle habits a child adopts can push things in one direction or another. So kids who are active, fit, and eat a lot of fruits and vegetables may drastically decrease their chances of developing metabolic syndrome — even if a close relative already has it.
^ Jump up to: a b Kato, Norihiro; Loh, Marie; Takeuchi, Fumihiko; Verweij, Niek; Wang, Xu; Zhang, Weihua; Kelly, Tanika N.; Saleheen, Danish; Lehne, Benjamin (2015-11-01). "Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation". Nature Genetics. 47 (11): 1282–93. doi:10.1038/ng.3405. ISSN 1546-1718. PMC 4719169. PMID 26390057.
[Guideline] Qaseem A, Wilt TJ, Rich R, et al, for the Clinical Guidelines Committee of the American College of Physicians and the Commission on Health of the Public and Science of the American Academy of Family Physicians. Pharmacologic treatment of hypertension in adults aged 60 years or older to higher versus lower blood pressure targets: A clinical practice guideline from the American College of Physicians and the American Academy of Family Physicians. Ann Intern Med. 2017 Mar 21. 166 (6):430-7. [Medline].
Hypertension is a worldwide epidemic; accordingly, its epidemiology has been well studied. Data from National Health and Nutrition Examination Survey (NHANES) spanning 2011-2014 in the United States found that in the population aged 20 years or older, an estimated 86 million adults had hypertension, with a prevalence of 34%.  Hypertension affects US men and women nearly equally, affecting an estimated 40.8 million men and 44.9 million women. 
[Guideline] Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2018 Jun. 71(6):e13-e115. [Medline]. [Full Text].