European Journal of Cardiovascular Medicine

In recent times, the prevalence of obesity has increased exponentially in developing countries due to the consumption of energy-dense food and sedentary lifestyle habits, thus facing the risk of obesity and its adverse consequences, particularly diabetes mellitus and coronary artery disease (CAD) ¹. The body mass index (BMI) is used to assess obesity and overweight, obesity is defined as BMI greater than or equal to 30 Kg/m2, and overweight is defined as BMI greater than or equal to 25 Kg/m^{2 2}. However, in Asians, the cut-offs for obesity and overweight are lower than WHO criteria i.e.≥25.0 Kg/m² and ≥23.0-24.9 Kg/m² respectively due to risk factors and morbidities. Globally, recent studies have reported that more than 1.9 billion adults are overweight and 650 million are obese ¹.  Many studies have shown that the prevalence of overweight population and obese individuals in India ranges between 30% -65% ³. It has been observed that 79% of people had abnormalities in one of the lipid parameters ⁴. The Adult Panel III (ATP III) from the national cholesterol education program has stated that elevated low- density lipoprotein (LDL), triglycerides (TGL), and lower high-density lipoprotein (HDL) are associated with overweight and obesity ⁵. In addition, BMI has been identified as a definitive risk factor for certain chronic diseases like hypertension, diabetes mellitus, and dyslipidemia ^6,7.

Obesity is associated with alterations in lipid parameters such as elevated triglyceride, very low- density lipoprotein (VLDL), Apo B, and non-HDL cholesterol levels ^{8, 9}. The major ill effects of obesity are increased risk of coronary artery disease, hyperglycemia, hypertension, and metabolic syndrome ¹⁰.  The core components of metabolic syndrome are elevated levels of triglycerides, elevated blood pressure, larger waistline, raised fasting blood glucose levels, and low HDL-cholesterol levels. In obese individuals, the alteration in these components has shown an association with elevated levels of small dense LDL which is considered to be the most atherogenic subfraction of LDL ¹¹ as they have decreased affinity for the LDL receptor, also enter arterial wall easily than large particles and bind dedicatedly to intra-arterial proteoglycans. Ultimately, small dense LDL particles are more susceptible to oxidation, which could result in an enhanced uptake by macrophages ¹². In addition, it is also observed that individuals with high concentrations of these particles are at increased risk for developing CAD ^{11, 13}.

In developing countries like India, due to industrialization and urbanization, the lifestyle has been modified which has led to the development of overweight and obesity and posing a risk to the health of the community. It is well known that obesity is coupled with elevated systolic and diastolic blood pressures, dyslipidemia, diabetes, etc. ¹⁴. The increased dimension of this problem has been identified in urban areas and high socio-economic groups compared to rural and low-socioeconomic groups.  With increased modernization, urbanization, and life style modifications, it is observed that an increased trend of hypertension in our population ¹⁵. Obesity which is generally calculated by BMI is considered to be main risk factors for hypertension ¹⁶ and the prevalence of hypertension increasing with increase in BMI ¹⁷.

The increased cardiovascular risk in type II diabetes mellitus (T2DM) can be a multifactorial, but atherogenic dyslipidemia characterized by elevated triglycerides and low levels of HDL cholesterol correlates well with the metabolic syndrome, contributing progressively to atherosclerotic cardiovascular disease (ASCVD) risk ¹⁸. As BMI increases, the abnormality in lipid levels also increases. Approximately 60-70% of patients who are obese are dyslipidemic, while 50-60 of patients who are overweight are dyslipidemic ¹⁹. Notably, obesity in children and young adults also leads to an increased prevalence of elevated triglycerides and decreased HDL levels ²⁰. The increased risk for cardiovascular disease in patients with obesity is partially accounted for by this dyslipidemia. It is essential to identify the individuals and population at risk is a responsibility of health professionals, health service institutions and governments, etc. Therefore, the present study was undertaken to identify the prevalence of obesity, overweight among patients attending cardiology outpatient department and to analyze their association with hypertension subtypes in northern Andhra Pradesh.

The present cross-sectional study was conducted on the subjects who have visited Cardiology outpatient department of NRI Medical College, Sangivalasa for routine cardiac check-up. A total of 310 individuals were included between the age group 30-45 years of both the gender for the study after getting approval from Institutional Ethics Committee. The known cases of cardiac disease, chronic illness, smoking, alcoholism, morbid obesity (BMI>40kg/m2) and patients who were already on lipid-lowering drugs were excluded from the study.

The subjects were counseled regarding the study and their height and weight were measured to find BMI. BMI was calculated as the total body mass divided by height squared. A 5mL of fasting blood sample was collected for lipid profile and blood glucose. The total cholesterol (TC), LDL cholesterol, HDL cholesterol and TGL were determined directly by using Biosystems automated biochemistry analyzer.

All the patients were divided into three groups according to consensus guidelines for Asian Indians viz. normal, overweight and obesity depending on the BMI. Patients with BMI 18.0-22.9 Kg/m² are considered as normal, 23.0-24.9 Kg/m² as overweight and ≥25 Kg/m² were as obese ²¹.  Patients with systolic blood pressure (SBP) <120 mm Hg and diastolic blood pressure (DBP) <80 mm Hg have been considered normal blood pressure. The SBP 120–139 mm Hg or DBP 80-89 mm Hg were classified as prehypertensive, SBP140–159 mm Hg or DBP 90-99 mm Hg were considered as stage I hypertension, whereas SBP of >160 mm Hg and DBP of >100 mm Hg were classified as stage II hypertension ²².

STATISTICAL ANALYSIS

Data distribution was studied by using Kolmogorov Smirnov test. Data obtained was expressed as mean ± Standard deviation for data showing a normal distributed, median inter quartile range for data which showed an on-normal distribution. The difference in the levels of lipid parameters between groups was studied by parametric independent samples T test, and among the three groups by analysis of variance (ANOVA). Pearson’s correlation or Spearman rank correlation analysis was performed to study the correlations among the parameters as appropriate. The significance was set at the p- value of <0.05. A Statistical analysis performed using Microsoft Excel Spread sheet (Microsoft Redmond, USA) and SPSS for windows version16.0 (SPSS Inc, Chicago, IL, USA).

During the study period, 310 subjects were included in the study. All the patients belonged to a northern Andhra Pradesh population from Andhra Pradesh. The clinical characteristics of the study subjects have been presented in Table 1. The mean age of males was 45.2±1.2 years and 42.8±1.6 years in the females. The risk factor profile of the patients revealed mean SBP in males was 146.9±21.1 and in females was 136.2±13.7 and found a significant difference of <0.0001. A significant difference was observed between males and females of SBP, DBP and in the levels of total cholesterol, triglyceride, and LDL. The levels are significantly increased in males compared to females. However, no significant difference was observed in HbA1C levels between males and females.

We compared fasting blood sugar (FBS), HbA1c, and lipid parameters with studied BMI groups which were given in table 2 and also found significant differences in SBP, DBP, TC, LDL and HDL between groups classified based on BMI. We checked the percentage of normal and abnormal lipid parameters based on BMI and found that highest percentage 92.9% of LDL was observed in BMI >25 group compared to other groups were given in Table 3.

We found that the prevalence of obesity and overweight was 60% and 20%, respectively. The prevalence of hypertension was 50%, and it was significantly higher in obese and overweight individuals (66.7% and 33.3%, respectively) (Table 4).

The study also found that the risk of hypertension increased with increasing BMI. The odds ratio for hypertension was 4.03 (95% CI: 2.13-7.64) for obese individuals and 2.23 (95% CI: 1.23-3.99) for overweight individuals, compared to those with normal weight. The correlation between SBP, and DBP with BMI and lipid parameters was given in table 5 and prevalence of hypertension based on BMI was given in table 6. BMI and triglycerides are significantly associated with SBP and DBP in both males and females having a p-value <0.05 (Fig 1). The correlation between BMI and blood pressures (SBP and DBP) in both males and females were depicted in Fig.2.

Table 1: Demographic and Biochemical Characteristics of study population

Note: FBS-Fasting Blood Sugar., BMI- Body Mass Index., SBP-Systolic Blood Pressure., DBP-Diastolic Blood Pressure., TC-Total Cholesterol., TGL-Triglycerides., LDL-Low Density Lipoproteins., HDL-High Density Lipoproteins.,

* p<0.05 is significant

Table 2: Comparison of FBS, HbA1c, SBP, DBP and lipid parameters with studied BMI groups

Note: * p<0.05 is significant

Table 3: Percentage of normal and abnormal lipid parameters based on BMI

Table 4: Prevalence of hypertension in both males and females

SBP and gender Chi-square=16.77, p<0.0002

DBP and gender Chi-square=23.94,  p<0.00001

Table 5: Correlation between SBP, DBP with BMI and lipid parameters

           in males and females

Note: * p<0.05 is significant

Table 6:  Prevalence of hypertension according to BMI

Fig. 1: Correlation between the Blood Pressure and Triglycerides in Males and Females

Fig. 2: Correlation between the BMI and Blood pressure in Males and Females

Obesity can result in over-serious health issues that there is no single cause to explain all the cases of obesity. However, obesity ultimately results from an imbalance between energy intake and energy expenditure. Even though, genetic predisposition does not automatically lead to the development of obesity, eating habits and patterns of physical activity may show a more significant role in the amount of weight gained. Additionally, a sedentary lifestyle as well as psychological factors (depression, low esteem, or absence of night sleep) can also largely contribute to weight gain ^23-26.

Our findings highlight a high prevalence of overweight/obesity and hypertension in a tertiary care center of northern Andhra Pradesh. The cross-sectional study conducted in a tertiary care center of Northern Andhra Pradesh, India found that the prevalence of obesity and overweight was 60% and 20%, respectively. The prevalence of hypertension was also high (50%), and it was significantly higher in obese and overweight individuals (66.7% and 33.3%, respectively). These findings are consistent with previous studies that have shown a strong association between obesity and hypertension ^{24, 25.}

Obesity is a complex metabolic disorder that is characterized by excessive body fat accumulation. It is associated with several chronic diseases, including hypertension, heart disease, stroke, T2DM, and certain types of cancer ²⁴. Hypertension is a condition in which the blood pressure is persistently elevated, and it is a major risk factor for heart disease, stroke, and kidney disease ^25.

The present study studied the percentage of normal and abnormal lipid parameters based on BMI and we found that 92.9% of LDL in BMI >25 group compared to other groups and prevalence of obesity and overweight was 60% and 20%, respectively. (Table 3 and Fig 1).We found that the prevalence of hypertension was significantly higher in obese and overweight individuals (66.7% and 33.3%, respectively). The study also found that the risk of hypertension increased with increasing BMI. The odds ratio for hypertension was 4.03 (95% CI: 2.13-7.64) for obese individuals and 2.23 (95% CI: 1.23-3.99) for overweight individuals, compared to those with normal weight. The observed association between overweight/obesity and hypertension is consistent with previous studies conducted in India and globally ²³. This association can be explained by several mechanisms, including excess fat deposition leading to insulin resistance, inflammation, and activation of the renin-angiotensin-aldosterone system, all of which contribute to blood pressure elevation ^{24, 25}.

The quantity of fat in diet of a person may have greater impact on weight gain than the number of calories it contains. The majority of fat calories are directly stored in fat cells, which add to the body's weight ²⁶ while carbohydrates and vegetable and proteins are converted to fuel almost immediately following consumption ²⁷. In addition, fat regimens result in excessive and abnormally higher levels of cholesterol in the blood (hypercholesterolemia). Depending on the balance between the fractions of saturated and unsaturated fatty acids, fat contained in the blood circulation can immediately affect certain organs such as liver and kidney, concomitantly with destructive through the formation of atherosclerosis, an infringement of medium and large arteries due to a buildup of fat inside of the arterial wall, termed visceral fat. The latter is mainly involved in metabolic syndrome ^{28, 29, 30}.

The high prevalence of overweight/obesity and hypertension pose a significant public health challenge in northern Andhra Pradesh. This underscores the need for multi-pronged strategies to address these issues. These strategies should include population-based interventions aimed at promoting healthy lifestyle choices like regular physical activity and a balanced diet, as well as early detection and management of overweight/obesity and hypertension through effective screening programs and counseling services.

There are several mechanisms, by which obesity can increase the risk of hypertension, including:

• Increased blood volume
• Increased insulin resistance
• Increased inflammation
• Activation of the sympathetic nervous system
• Increased renin-angiotensin-aldosterone system activity ²⁵, ³¹

The high prevalence of obesity and hypertension in north east India is a major public health concern ²³. It is important to develop and implement public health interventions to promote healthy weight and lifestyle changes in this region in order to reduce the burden of obesity and its associated chronic diseases, including hypertension ³². Some specific interventions that could be implemented include:

• Health education programs to raise awareness of the risks of obesity and hypertension.
• Promoting healthy eating habits and physical activity.
• Making healthy foods more affordable and accessible.
• Restricting the marketing of unhealthy foods and beverages.
• Providing support for individuals who are trying to lose weight or maintain a healthy weight ²⁷.

The findings of the present study suggest that obesity and overweight are major risk factors for hypertension in northern Andhra Pradesh. The treatment of obesity or over weight itself requires guidelines proposing deep lifestyle modifications target to reduce body weight, thereby consuming a low-caloric diet with a total of 500–1,500 for men and 500–1,200 calories for women. Public health interventions to promote healthy weight and lifestyle changes are needed to reduce the burden of hypertension in this region.

By addressing the problem of obesity, we can reduce the burden of hypertension and other chronic diseases in northern Andhra Pradesh and improve the health and well-being of the population.

Public health implications

The findings of the present study underscore the need for public health interventions to promote healthy weight and lifestyle changes in Northern Andhra Pradesh. These interventions should focus on increasing physical activity, improving diet, and reducing obesity.

Limitations

The study was conducted in a single tertiary care center, limiting its validity to the wider population. Additionally, the cross-sectional design cannot establish causal relationships between overweight/obesity and hypertension.

Future Directions

Further research is needed to explore the complex interplay between environmental, social, and genetic factors that contribute to the high prevalence of overweight/obesity and hypertension of population living in northern Andhra Pradesh. Additionally, interventional studies evaluating the effectiveness of different strategies for preventing and managing overweight/obesity and hypertension are needed.

This study highlights a high prevalence of overweight/obesity and hypertension in a tertiary care center of northern Andhra Pradesh. The significant association between these two conditions underlines the need for comprehensive strategies to address them. These strategies should focus on promoting healthy lifestyles, early detection and management of overweight/obesity and hypertension, and further research to understand the factors contributing to these conditions. By taking these measures, we can help to reduce the burden of non-communicable diseases and improve the health of individuals and communities in Andhra Pradesh.

Conflict of Interest:None

Funding Support :Nil

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