Hypertension is a major public health problem all over the world. As India is progressing towards industrialization and improved mechanization, it has led people towards decreased work load and increased sedentary lifestyle. This has resulted in a rising trend of chronic lifestyle diseases like Hypertension (HTN), Diabetes Mellitus and Obesity.¹ The incidence of hypertension is increasing year after year and the prevalence of hypertension is increasing day by day due to increased life expectancy and aging population. The adjusted prevalence of hypertension according to JNC7 and 2017 ACC/AHA criteria was 29.7% and 63.8% respectively; an absolute increase of 34.1%. Adjusted prevalence among males and females was 68.7% and 54.2% respectively, using the 2017 ACC/AHA criteria. The prevalence standardized as per WHO standard population was 30.7% and 66.7% for JNC7 and ACC/AHA 2017 criteria, respectively. Among them 4.9%, 55.3%, 11.9%, 12.8%, 5.5% and 1.6% subjects were in the age group 18-19, 20-44, 45-54, 55-64, 65-74 and ≥75 years respectively.²

Microalbuminuriaa is a state of increased vascular permeability particularly in the kidney. Microalbuminuria has been traditionally defined as urinary albumin excretion rate between 30 mg/24 hours and 300 mg/24 hours or urine albumin creatinine ratio between 30 mg/g & 300 mg/g in an early morning sample. It is pertinent to note that these cut-off values have been primarily defined for proteinuria in diabetic individuals, and are yet to be rigorously validated in non-diabetic individuals.³ Microalbuminuria possibly reflects a state of increased renal endothelial permeability and is an easily measured marker of rather diffuse endothelial dysfunction, low grade inflammation and vascular disease burden. Therefore, screening for microalbuminuria and follow up of patients is needed. Regarding the determination of microalbuminuria, there had been considerable variation in the performance of diagnostic tests. 24-hour urine albumin excretion remains the gold standard, but impractical. Regarding association between microalbuminuria and hypertension quantitative estimation of urinary albumin excretion (UAE) has revealed higher frequency of microalbuminuria in patients with hypertension than in normotensive population. This difference in the incidence of micro-albuminuria in these studies may be related to the severity and control of hypertension, selection criteria, racial differences etc. Microalbuminuria has been determined as an important prognostic indicator and has been reported to be associated with increased cardiovascular risk and progressive renal damage.⁴

Reliable data on the prevalence of microalbuminuria in the general population and its association with cardiovascular risk factors is limited. Till now, there is little data available regarding screening and early treatment of hypertensive patients with microalbuminuria, as in the case of microalbuminuric non diabetic subjects.⁵ With this perspective this cross-sectional study of microalbuminuria in non-diabetic hypertensive patients was undertaken to study prevalence of microalbuminuria in non-diabetic hypertensive patients.

This study was approved by the Institutional review board and Institutional ethics committee and was conducted from January 2024 to December 2024 at the Department of General Medicine, S.S. Institute of Medical Science & Research Center, Davangere.

It was a hospital-based cross-sectional study done among non-diabetic essential hypertensive in-patients with blood pressure above 140/90 mm of Hg and aged more than 30 years of either gender and admitted in general medicine ward of a tertiary care teaching institution in South India. Unwilling patients, diabetic patients, patients with renal disease, heart failure, macroalbuminuria and those with a positive history or clinical signs of ischaemic heart disease were excluded from the study.

The sample size was calculated according to the formula 4PQ/L2 where; P is the prevalence, Q is 100-Prevalence, and L is an allowable error. From a study conducted by Sharan Badiger, where the prevalence of microalbuminuria in hypertensive patients was 63 %, the sample size was calculated to be 186. All consecutive patients who satisfied the selection criteria were selected. The study tool used was a previously designed semi-structured questionnaire. Study variables included microalbuminuria, left ventricular hypertrophy (LVH), hypertensive retinopathy (HRT), duration of hypertension and sociodemographic variables like age and gender.

Informed written consent was taken from the study patients before they were enrolled for the study. Relevant details of the patients were collected using a semi-structured questionnaire. Urine microalbumin was tested in a urine spot sample. Echocardiography, ECG interpretation and fundus examination were done in the Department of Internal Medicine.

Hypertension is defined as office systolic BP (SBP) values > 140 mmHg and/or diastolic BP (DBP) values > 90 mmHg. The 2018 ESC/ESH Guidelines for the management of arterial hypertension state that there are 3 grades of hypertension -Grade 1: SBP 140–159 mm of Hg and/or DBP 90–99 mm of Hg. Grade 2: SBP 160–179 mm of Hg and/or DBP 100–109 mm of Hg. Grade 3: SBP > 180 mm of Hg and/or DBP > 110 mm of Hg.

A person is said to have microalbuminuria if his albumin to creatinine ratio is in the range of 30 - 300 mg/g creatinine in a urine spot sample. Left ventricular hypertrophy was diagnosed by echocardiography when left ventricular posterior wall or interventricular septal thickness was greater than 1.3 mm. All the patients were subjected to direct fundoscopy to assess retinal vasculature. It was also used to examine the optic disc for signs of hypertensive retinopathy. Keith Wagener Barker classification10 was used for grading of retinopathy. Grade 1 and 2 were considered as early retinopathic changes whereas grades 3 and 4 were considered as advanced retinopathy.

Statistical Analysis:

Data collected were entered in SPSS software. Quantitative variables were expressed as means. Qualitative variables were expressed as proportions. Association of outcome variables like left ventricular hypertrophy and hypertensive retinopathy were analysed using the chi-square test.

During the eight months, 186 patients who were admitted for various reasons and had a blood pressure reading above 140/90 mm of Hg were enrolled for the study after careful analysis of the exclusion criteria. Most of them were above 50 years and the mean age of the group studied was 55 ± 8.89 years. Of this, the mean age in the males was 56.6 + 8.9 years and that of the females was 52.6 + 7.0 years. The majority of the cases with microalbuminuria was found in the higher age group, 59.75 ± 16.32 years in males versus 57.9 ± 17.58 years in females. There was male sex preponderance in our study with 65 % (120 patients) of them being males and 35 % (66 patients) females.

Table 1: Baseline Gender Characteristics

Table 2: Left Ventricular Hypertrophy (LVH) and Microalbuminuria

Table 3: Hypertensive Retinopathy and Microalbuminuria

Table 4: Microalbuminuria and Duration of Hypertension

Table 5: Microalbuminuria and Hypertensive Severity

Our study correlated well with other studies on many levels. Most of the people were middle-aged and the mean age was 55 + 8.89 years. Our study continues to show that there is still an increased prevalence of essential hypertension in middle aged people although there is upcoming evidence of young hypertensives in other parts of India. Gender-wise, our study suggests that females are developing hypertension at early ages compared to men (52.6 years Vs 56.6 years) probably due to the early onset of menopause in females. There was slightly increased age preponderance in males. In spite of this, gender did not pose any higher risk for the presence of microalbuminuria.⁶

In our study, microalbuminuria was seen in 68 % of the patients. This was similar to studies conducted by Poudyal et al. (62.5 %), Rameez et al. (69 %) but much higher than the study by Stalin et al. (24.3%) and Hitha et al. (26.67%). Studies from Nigeria as in Busari et al. showed a lower prevalence of microalbuminuria (32.2 %) and a study in the Iranian population by Hemmati et al. showed a much lower prevalence of 5.6 %. Variations in different studies conducted could be due to different criteria used in selection, inpatients versus outpatients in the study population, differences in the methods used for detecting microalbuminuria, the severity of hypertension, different age, population and ethnicity, and coexistent comorbidities.⁷

People with increasing age are more likely to have microalbuminuria in our study also, as observed in other studies like Wachtell et al. (beta = .095, P < .01) and Stalin et al. As expected, we noticed that long-standing high blood pressure patients with or without treatment were associated with an increased prevalence of microalbuminuria.⁸ We also studied the association of microalbuminuria with the severity and duration of hypertension. We noticed that there was a positive association between microalbuminuria and long-standing hypertensive patients (P < 0.0001). This study had similar findings as the study conducted by Kartik et al. (Chi-square value of 27.38 and a P < 0.001) and Stalin et al. According to Stalin et al. long-standing hypertensives (8.44 ±5.58 years) had more increased incidence of microalbuminuria.⁹

In opposition to the observations made in the ETODH study, we noticed a strong relationship between hypertensive retinopathy and microalbuminuria. The predominance of microalbuminuria was higher among those with hypertensive retinopathy in this review (51.7 %). The higher predominance of microalbuminuria in patients with hypertensive retinopathy correlated with the study by Stalin et al. In the review by Busari et al. advanced hypertensive retinopathic changes, i.e., Grades III-IV were more often seen in patients with microalbuminuria than in those without microalbuminuria (22.6 % versus 1.5 %). This shows that there is a critical relationship between microalbuminuria and target organ damage in essential hypertension and microalbuminuria can be viewed as an early forerunner of target organ damage.¹⁰

Most of microalbuminuria positive cases were found appropriated among higher ages. In this study, gender didn't represent a more serious danger for microalbuminuria. There was a huge measurable affiliation present between the microalbuminuria and span and the seriousness of hypertension. There is also a huge measurable affiliation present between microalbuminuria and target organ damage like LVH and retinopathy in hypertensive patients.

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