**2.4 Diabetes mellitus**

Diabetes mellitus (DM) is caused by insufficient production of insulin by the pancreas or resistance by end-organ tissues and presents as a high blood glucose. There are three types of DM, namely, type 1, type 2, and gestational diabetes. Type 1 DM is an autoimmune disorder and usually takes place in early childhood and adolescents, gestational DM occurs during the second or third trimester of pregnancy, increases the future risk of those patients to type 2 DM [41–43]. Type 2 DM, the most common form accounts for 90–95% of diagnosed DM and continues to be rapidly growing worldwide and in the USA [44]. Globally, the prevalence of DM is escalating and its incidence in 1985 was 20 million compared to 382 million in 2014 [45]. The current estimation by the International Diabetes Federation expects that 592 million people will have DM by 2035 [46]. China and India have highest number of people with diabetes estimated at 69 million and 109 million, respectively and these numbers are expected to rise to 123 million and 150 million by 2040 [47]. A

*Role of Functional Food in Treating and Preventing Cardiovascular Diseases DOI: http://dx.doi.org/10.5772/intechopen.96614*

#### **Figure 1.**

*Possible mechanisms of physical activity that help in decreasing CVDs risk [37].*

close association exists between DM and CVDs. The most familiar cause of mortality and morbidity in diabetic patients is CVDs since DM results in complications of both microvascular and macrovascular. Complications such as IHD, ischemic stroke, and amputations because of foot infections are examples of macrovascular. The comparative risk for CVDs morbidity and mortality in adults with DM varies from 1 to 3 in men and from 2 to 5 in women to those with no DM [48]. Many diabetic patients die due to IHD or stroke and both are often registered as the cause of death, not DM [2]. A number of evidences exist that demonstrate that the relationship of type 2 DM and associated cardiovascular risk promote the progressive nature of the vascular damage, leading to atherosclerosis [49]. Cardiovascular deaths account for 44% of death in those with type 1 DM and 52% of deaths in type 2 DM [50]. Debate still remains if the relationship between DM and CVD is associated with diabetes status itself or the risk factors diabetic patients are prone to.

#### **2.5 Obesity and overweight**

According to the World Health Organisation data, 39% of the global population above 18 years of age is overweight and of these, 13% are obese. Obesity is an abnormal or excessive fat accumulation in adipose tissue to the degree that health might be compromised [51]. Obesity increases the risk for CVDs since it increases the load of the atherosclerotic plaques, characterised by significant infiltration of macrophage and plaque fluctuation [52]. People who accumulate abnormal body

fat, particularly at the waist, are at higher risk to have stroke and heart disease even if they do not have other risk factors. The incidence of overweight and obesity among adults in low-income countries varies from 4.7–21.0% and from 13.0–42.7% in upper-middle-income countries [53]. Different studies have demonstrated association between obesity and CVDs such as heart failure and cardiac death. Accumulation of abnormal body fat leads to various metabolic changes that increase the common risk factors of CVDs and affects systems modulating inflammation [54]. Recent studies have demonstrated that weight loss in individuals who are overweight and obese reduces the incidence of diabetes and CVDs. The benefit of weight reduction in overweight and obese individuals with or without hypertension is low blood pressure and serum triglycerides, and increased high-density lipoprotein [55, 56].
