Journal of Medical Sciences and Health

Introduction

Pre-hypertension (Pre-HTN), also known as high normal blood pressure (BP), is defined as “Systolic blood pressure (SBP) ranging between 120-139 mmHg and/or diastolic blood pressure (DBP) ranging between 80-89 mmHg.1 It has been reported that pre-HTN could significantly increase the risk of hypertension, target organ damage, cardiovascular events, and mortality. ² Many physicians worldwide have observed a high frequency of pre-HTN as well as hypertension in the patients of diabetes mellitus. The studies have reported that the prevalence of hypertension had increased as much as six-fold among diabetic compared with nondiabetic patients. ³ Therefore, HbA1c, the indicator of glycaemic control, may be correlated with the hypertension stage in diabetic patients. ⁴

Microalbuminuria, defined as persistent elevation of albumin in the urine in the range of 30-300 mg/day (20-200 µg/min), is associated with the susceptibility of an individual to cardiovascular (CV) disease in pre-diabetes and pre-hypertension. ⁵ It is therefore an ideal target for early primary prevention using CV protective therapy regimens and can be used as biomarker. ⁶ 

The changes in the lifestyle and eating habits, which has occurred more in the urban population as compared to rural population, are added risk factors. The urban population can be defined as people living in urban areas as defined by national statistical offices. The urban population has greater population density and overall, more compact than rural population ⁷ . Urban people have adopted a sedentary lifestyle, unhealthy food habits and addictions like tobacco smoking, alcoholism which increases the risk for many lifestyles related diseases like Diabetes mellitus, Hypertension etc. Diabetes mellitus (DM) is a condition where blood sugar (glucose) level is are higher than normal due to body’s inefficiency in utilization of blood glucose or storing of blood glucose for energy ⁸ . Therefore, apart from traditional risk factors like duration of diabetes, glycaemic control (HbA1c), microalbuminuria, dyslipidaemia, obesity (BMI, Waist circumference), age there are some non-traditional risk factors that include food habits, tobacco smoking, alcoholism and physical inactivity in a particular patient and have to be studied in detail so that an insight into the prevention and proper treatment planning can be made.

Recently both pre-HTN and pre-diabetes have caught the attention of clinicians as well as epidemiologists due to their high prevalence rate as compared to hypertension and DM and affecting the prime productive years of life. Further, targeted intervention at this stage will prevent or postpone progress to overt disease and will reduce the cardiovascular risk.

Though several studies have reported the prevalence of Pre-HTN among DM in the Indian population, the reports are conflicting. Furthermore, there is a paucity of data on the correlation of pre-HTN with dietary habits, demographic profile, HbA1c, waist circumference, lipid profile and urinary albumin level. This study tried to evaluate the prevalence of Pre-HTN in DM and other correlations in the North Indian population so that early identification of the risk factors will help in proper treatment strategy that will reduce the complications of hypertension in the long run and will also improve the quality of life of the patients.

Material and Methods

This comparative, cross-sectional and observational study was conducted in the Department of General Medicine at Jaipur Golden Hospital, Delhi, India from November 2020 to December 2021. Ethical clearance was obtained from the Institutional Ethical Committee for Human Research (IEC-HR) prior to execution of the study. The present study was according to declaration of Helsinki. Prior written informed consent was obtained from the participants.

Results

The prevalence of Pre-HTN in DM patients was calculated. The participants were then categorized in two groups. Group I comprises DM cases with Pre-HTN and Group II comprises normotensive DM cases. Group I and Group II was compared with respect to age, gender, duration of DM, dietary habits, tobacco smoking, alcoholism, obesity (BMI, Waist circumference) HbA1c, lipid profile parameters, urinary albumin level and physical activity. The correlation between lipid profile parameters and systolic and diastolic blood pressure was also evaluated. Prevalence of the Pre-HTN in DM patients was 42% and significantly more in the males (56.14%) as compared to females (23.25%) (Table 1). Group I had higher mean age of presentation (47.52 years vs 39.37years). Group I had also reported significantly higher intake of salt and junk food with increased waist circumference (Table 2). In our study, the percentage of people with high salt (>11 grams) intake was higher in the pre-hypertensive group (23.72%) as compared to the normotensive group (20.09%). Similarly, the percentage of people with increased frequency of junk food intake per week was lower in the normotensive group (19.82%) as compared to 26.36% in the pre-hypertensive group. The mean waist circumference was smaller (73.64cm) in Group II than Group I (87.05 cm) Glycaemic control was poor though non-significant in Group I as compared to Group II (Table 2). There was significant positive association of tobacco smoking and alcohol intake in development of pre-HTN as evident from Table 3. The present study reported that 44 participants had the habit of cigarette smoking, out of whom 25 were found to be pre-hypertensive. Among 42 participants who reported that they had a habit of drinking alcohol, 29 had pre-HTN (Table 3). Increased duration of DM, low physical activity and increased BMI were significantly contributing to pre-HTN development in diabetic patients (Table 3). In this study, 28 out of 42 DM patients with pre-HTN had high weight (7 were overweight, 5 were class I obese, 10 had class II obesity, and 6 were class III obese) (Table 3). A higher BMI shows a greater prevalence(p<0.05) of pre-HTN. Lipid profile parameters were significantly deranged in Group I with high triglycerides, high total cholesterol, high low-density lipoprotein (LDL-c) and decreased high density lipoprotein (HDL-c) (Table 4). The mean urinary albumin level was also in the range of microalbuminuria in significantly higher percentage in Group I (29.35%) as compared to Group II (8.96%). Dyslipidaemia, especially high Triglycerides (r=0.867) had significantly strong correlation with Pre-HTN in DM patients (Table 5).

Discussion

This study attempted to find the current prevalence of Pre-HTN among DM in the North Indian urban population and association of pre-HTN with lifestyle related parameters (dietary habits, tobacco smoking, alcohol consumption, physical activity, Obesity (waist circumference, BMI), HbA1c, lipid profile parameters and urinary albumin level.

As per the finding of this cross-sectional study, reported prevalence of the Pre-HTN in DM patients was 42% and more preponderant in the males (56.14%) as compared to females (23.25%) (Table 1). Similar study by Metri et al., had reported even a higher prevalence of pre-HTN in DM (59.7%) and prediabetes (57.3%) cases. Increasing age and male sex were significantly associated with both pre-HTN and hypertension. ¹⁵ DM is an important risk factor for hypertension. The pathogenesis of both DM and hypertension indicates towards common mechanism namely increased inflammation, altered autonomic function and disturbed renin angiotensin aldosterone system. ¹⁶

Our study suggests that people belonging to the pre-hypertensive group had higher salt and junk food intake as compared to the normotensive group (Table 2). Consumption of salty foods and the addition of extra salt in meals was significantly associated with pre-HTN. It has been reported that consuming salty foods on a regular basis was significantly associated with an increased risk of pre-HTN. ¹⁷ There are findings from different studies suggesting that decreased frequency of junk food intake leads to favourable lipid profile and lower BMI and reported a significant association of junk food consumption with elevated blood pressure. ¹⁸ Waist circumference in DM with pre-HTN was significantly higher and there is study reporting that waist circumference had a positive odd with Pre-HTN. ¹⁹ There was no significant difference in HbA1C level in two groups suggesting that degree of hypertension was not associated with diabetic control. Contrary to our findings, there are reports concluding that HbA1c was significantly associated with blood pressure. ^20, 21

Our study reported that the occurrence of pre-HTN was more in DM cases with tobacco smoking alcohol intake, high BMI and reduced physical activity (Table 3). Parthaje et al. had reported similarly that individuals with tobacco and alcohol use, obesity, and low physical activity had significantly higher levels of prehypertension and hypertension. ²² In a meta-analysis by Whelton et al., it had been reported that increment in total daily physical activity reduces the hazard ratios of hypertension. Apart from exercising >3 times/week, intermittent small episodes of 10 min walk, collectively 30 min walk reduces systolic blood pressure in pre-HTN. Studies had concluded in their finding that the odds of being hypertensive and pre-hypertensive is more among tobacco smokers and alcohol consumer.13, 23 Though the exact mechanism of hypertension in alcoholics is not clear but imbalance of CNS, impaired baroreceptors, stimulated renin angiotensin system, high sympathetic activity and increased vasoconstriction with loss of relaxation are proposed mechanisms 24. In this study out of 42 patients having pre-HTN, 7 were overweight, 5 patients were class I obese, 10 had class II obesity and 6 were class III obese (Table 3) and Group I had significantly higher waist circumference (Table 2). Overweight, obesity, and abdominal obesity were significantly associated with pre-HTN and hypertension 25. Obesity leads to onset of hypertension through interaction of environmental, genetic, lifestyle and dietary factors and leads directly to renal, cardiac, and vascular dysfunction through impaired inflammatory and immunological response. 26

Lipid profile parameters were significantly deranged in DM with pre-HTN as compared to normotensive DM cases (Table 4). A significant positive correlation was found between SBP and DBP with dyslipidaemia (p <0.05) (Table 5) in pre hypertensive DM patients only. It has been reported earlier that youths with altered serum levels of TC, HDL-C, or non-HDL-C had either high or borderline BP. 27 Therefore, Dyslipidaemia is an independent risk factor for prehypertension and hypertension development especially high triglyceride level had a very strong positive correlation (r=0.867). Total cholesterol (r=0.67) also had strong positive, and HDL-c had a moderate negative(r=0.54) correlation with development of pre-HTN. A study reported by Chen S et al. suggests that the risk of hypertension increases by 0.2% for every 1 mg/dl rise in Total cholesterol, LDL-c, and non-HDL-c. 28 Both triglyceride and HDL-c are inflammatory and metabolic predictor.

The mean urinary albumin excretion was also in the range of microalbuminuria in significantly higher percentage in DM with pre-HTN (29.35%) as compared to normotensive (Table 4). A study reported earlier that microalbuminuria was seen 22.2% of isolated prediabetics, 25% of isolated pre-hypertensives and 58% of subjects with both pre-HTN and prediabetes with significant association of microalbuminuria with cardiac changes. A study reported by Anjaneyaprasad et al. on 500 prediabetic patients, had concluded that Prediabetes patients with higher microalbuminuria and CRP levels had significantly elevated lipid levels. 28

Effective management of risk factors is central to the effective prevention and management of NCDs, and for limiting the substantial socioeconomic burden imposed by these conditions. 29 This requires the cooperation of scientists, the medical community, and policymakers to facilitate the development and implementation of prevention and control strategies for hypertension in patients with type II diabetes mellitus. We strongly recommend periodic screening of both BP and blood glucose to allow both hypertension and diabetes to be detected, and to facilitate early intervention with the goal of preventing complications. In addition, education and supervised implementation of a healthy lifestyle including physical activity, a healthy diet, and stress management should be implemented in patients with type II diabetes and hypertension. Complementary therapies such as yoga have also been shown to make a contribution to the prevention and management of type II diabetes and hypertension. 30