European Journal of Cardiovascular Medicine

Hypertension and dyslipidemia are the two co-existing and synergizing major risk factors for cardiovascular diseases. ^[1] The cellular constituents of blood affect blood volume and viscosity, thus playing a pivotal role in regulating blood pressure. ^[2] Overweight and obesity are critical determinants of adverse metabolic changes including, an increase in blood pressure. ^[3]

Hypertensive retinopathy is among the vascular complications of essential hypertension. It is known that; the autoregulation of the retinal circulation fails as blood pressure increases beyond critical limit. ^[4] However, elevated blood pressure alone does not fully account for the extent of retinopathy. There are cases in which retinopathy was resolved despite the persistence of high blood pressure. In addition to the effect of high blood pressure, other factors and humoral components probably take part in hypertensive retinopathy's pathogenesis. ^[5]

Many case-control & prospective studies have proved a strong & graded positive association of serum or plasma total cholesterol concentrations with coronary artery atherosclerosis, extending over a wide range of total cholesterol & LDL- cholesterol concentrations. ^[6]

Data about the correlation between serum lipoproteins & apoproteins concentrations & atherosclerosis were obtained from chronic heart disease studies. Fewer data are available on lipids & related variables as risk factors for stroke & cerebrovascular diseases caused by atherosclerosis. ^[7] Only very little data on lipids & atherosclerosis of peripheral arteries, particularly those of lower limbs. ^[8]

Although atherosclerotic changes were described in retinal arteries half a century ago (then called arteriosclerotic or arteriolosclerotic), there are no data on lipoproteins and retinal artery atherosclerosis. ^[9]

Hyperlipidemia contributes to the process of arteriosclerosis, which develops even faster in the presence of hypertension or diabetes mellitus. Hyperlipidemia or dyslipidemia is known to be an essential risk factor in hypertensive patients. ^[10]

Dyslipidemia in itself is known to be a risk factor for retinopathy & other ocular abnormalities. When it is associated with diseases like diabetes, hypertension the outcome is complicated. Its role in association with diabetic retinopathy and age- related maculopathy is well proven. ^[11]

Dyslipidemia in hypertensive patients may act as a predisposing risk factor, an aggravating or complicating factor. Understanding various ocular manifestations, a spectrum of findings, and their association with lipid profile components (LDL, HDL, VLDL, Total Cholesterol & Triglycerides) may be helpful in risk stratification and the tailoring of antihypertensive and lipid- lowering treatment. ^[12]

Hence this study assesses the association between concentrations of various serum lipids, lipoproteins, retinal changes & also other ocular manifestations in patients with essential hypertension.

The present study was a cross-sectional study, and it was conducted on 100 patients in the Department of Ophthalmology at Tertiary Care Teaching Hospital from January 2022 to December 2023.

All the patients were clinically examined& demographic information such as age, sex, residence, and other general and systemic examination information, case history, past medical history, complaints, etc., was collected and recorded in the Proforma prepared for this study purpose.

INCLUSION CRITERIA:

• Patients diagnosed with systemic hypertension (>140/90 mm Hg) areincluded in the
• All males and females of age above 30.

EXCLUSION CRITERIA:

• Normotensive patients.
• Patients suffering from ocular diseases like chorioretinitis and uveitis willbe excluded from the
• Patient with ocular media haze in both eyes to interfere with a detailedexamination of

Data is obtained using a proforma withthe informed consent of the patient. A detailed history will be taken from each patient, after which it was evaluated as follows.

1. She detailed the hypertensive status of the patient.
2. She detailed an ophthalmic examination of the patient
3. She detailed the lipid profile of the patient and other necessaryinvestigations

   CLINICAL EVALUATION

   The patients were evaluated as follows

   1. Detailed hypertensive status of the
   • Age of onset
   • Duration of the disease
   • Any medications
   • Associated conditions like diabetes, renal, cardiovascular,cerebrovascular
   • Family history
   • Other risk factors like smoking, alcohol, tobacco use were
   2. Detailed Ophthalmic Examination;
   • The patient was enquired about any ocular complaints, in particular,visual loss and its
   • Best-corrected Visual
   •  
   • Detailed external
   • Slit-lamp examination. Detailed fundus examination;

   After anterior segment examination, pupils were dilated with Tropicamide orCyclopentolate eye drops. Detailed fundus evaluation with-

   • Direct
   • Indirect
   • Slit-lamp bio-microscopy using 90D or 78D
   • Findings were recorded in colored fundus

   Staging of retinopathy was done using Modified Keith-Wagener-BarkerClassification 12

    

   Investigations

   • RBS, Complete blood profile
   • Urine routine and microscopic examination
   • Fasting serum lipid
   • Other investigations like Blood urea, serum creatinine, FBS, Chest x- ray ECG- ECHO, CT scan were done based on clinical diagnosis & suspicion of end-organ dysfunctions

   After complete evaluation;

    

   STATISTICAL ANALYSIS: -

   The data has been entered into MS-Excel, and statistical analysis has been done using IBM SPSS Version 25.0. For categorical variables, the data valuesare represented as numbers and percentages. To test the association between the groups, the chi-square test was used. For continuous variables, the data values are shown as mean and standard deviation. To test the mean difference between the three groups, an ANOVA test with a post hoc test was used. To test the correlation between the groups, Pearson’s correlation test was used. All the p values having less than 0.05 are considered statistically significant.

Table-1: Patient’s characteristics in the present study

In this study, 14.00% of patients had an age between 30 to 40 years, 20.00% of patients had an age between 40 to 50 years, 30.00% of patients had an age between 50 to 60 years, and 36.00% of patients had an age greater than 60 years.

In this study, 66.00% are male patients and 34.00% are female patients.

In the duration of hypertension, 49.00% of patients had hypertension in the duration of 0 to 5 years, 33.00% of patients had hypertension in theduration of 6 to 10 years, 12.00% of patients had hypertension in the duration of 11 to 15 years, and 6.00% of patients had hypertension in the duration of >15 years.

In this study, 68.00% of patients had fundus changes, and 32.00% had no fundus changes.

According to the retinopathy grade, 29.00% of patients had average grades, 18.00% of patients had Grade-I, 35.00% had

Grade-II, and 18.00% had Grade-III.

According to the severity of retinopathy, 63.00% of patients had Grade-I, 37.00% had Grade-II of the severity of hypertension.

According to vascular signs, 14.00% of patients had vascular signs,and 86.00% had no vascular signs.

According to the history of stroke, 24.00% of patients had astrokehistory, 76.00% hadn’t a history of stroke

Table-2: Mean difference between patients with retinopathy and withoutretinopathy including Clinico-demographic and biochemical profile

*P<0.05 - Significant

Table-2 showed that the clinico-demographic & biochemical profile of the patients with retinopathy and without retinopathy. In lipid profile, the mean±SD of serum triglycerides in retinopathy (130.29±40.20) was significantly higher than the mean±SD of serum triglycerides in non- retinopathy (113.16±33.05) [P=0.0384]. Other parameters of lipid profile such as TC (P=0.5966), LDL (P=0.180), HDL (P=0.8017) showed insignificant results while comparing with and without retinopathy.

Table-3: Relationship between Severity of Hypertension and Grade ofRetinopathy

Chi-square value = 1.557, P-value = 0.669 (Not Sig.)

Table-3 showed the Relationship between the Severity of Hypertension and the Grade of Retinopathy. In the Grade-II retinopathy patients, the number of patients with grade I hypertension were the majority (36.50%). However, there is no statistically significant association between the group of the severity of hypertension and grade of retinopathy (P=0.669, Not Significant). The graphical representation was shown in Figure-5.

Table-4: Comparison of demographics and serum lipid parametersbetween sub group of normal corneas and corneas with ARCUS

*P<0.05 –Significant

The mean±SD of TC was higher in the patients withARCUS (189.60±11.08). However, there is no statistically significant difference between the mean of ARCUS patients for TC (P=0.862).

The mean±SD of LDL was higher in the patients with ARCUS (39.48±3.89) However, there is no statistically significant difference between the mean of a patient with ARCUS for LDL (P=0.083).

The mean±SD of HDL was higher in the patient with ARCUS (127.08±26.02. However, there is no statistically significant difference between the patient with OS and without OS for HDL (P=0.3037).

The mean±SD of sr. TGL was higher in the patient with ARCUS (133.06±26.02). There is a statistically significant difference between the patient with OS and without OS for Sr. TGL (P=0.04).

The mean±SD of HDL & LDL ratio was higher in the patient with ARCUS (3.27±0.71). However, there is no statistically significant difference between the ratio of HDL & LDL (P=0.866).

In the present study, diastolic BP was 90.02 mm of Hg in the retinopathy group and 92.26 mm of Hg in the No retinopathy group, which was not statistically significant. Mean systolic BP in the retinopathy group 162.22, and No retinopathy group was 160.22, showing no statistical significance (P=0.6614). The present study shows no significant correlation (P=0.669) with severity of hypertension and retinopathy. The mean duration of hypertension was 6.685±5.22 years was observed in the total study population. Patients with retinopathy had a mean duration of hypertension of 6.75 years, patients with No retinopathy had 6.56 years. In our study, out of 69 patients with retinopathy, most of the patients had more than five years, whereas those without retinopathy belonged to < 5 years. Overall the association was statistically significant. (P=0.047).

Several studies have confirmed the   close   connection   between   signs   of hypertensive retinopathy and elevated blood pressure. ²⁶ Two studies have further evaluated the effect of a history of elevated blood pressure on the occurrence and may be more indicative of the severity of recent hypertension. ³¹ specific retinal signs.   In   both   studies, generalized retinal arteriolar narrowing and arteriovenous nicking were associated with an elevation in blood pressure that had been documented six to eight years before the retinal assessment; the studies were controlled for concurrent

 blood-pressure levels. This association suggests that generalized narrowing and arteriovenous nicking are markers of

vascular damage from chronic hypertension. In contrast, other signs (focal arteriolar narrowing, retinal hemorrhages, microaneurysms, and cotton-wool spots) were related to current but not 31,32 previous blood-pressure levels

Furthermore, the observation of retinopathy signs in people without a known history of hypertension suggests that these signs may be markers of a prehypertensive state. For example, generalized and focal narrowing of the retinal arterioles has been shown to predict hypertension risk in normotensive 58 33 persons. other factors unrelated to hypertension (e.g., hyperglycemia, inflammation, and endothelial dysfunction) may also be involved in the pathogenesis of retinopathy.

Now days, there have been many studies demonstrating a correlation between increased arterial blood pressure and altered lipid profiles, and there has been an especially positive correlation between high cholesterol levels 59 and blood pressure.

It was observed more than 35 years ago that nearly two-thirds of patients with atherosclerotic retinal changes have had atherosclerotic changes in other arteries and vice versa.60 - 62 However, in these patients, the trials did not establish the serum lipids and apoproteins. The arteries analyzed by ophthalmoscopy (branches of the central retinal artery) do have all the layers (endothelium–intima, basement membrane, media with smooth muscle cells, and adventitia) and resemble small arteries in other organs, including the heart and brain. Arterioles with a smaller diameter than 63 and 134 μm lack internal elastic lamina and a continuous layer of smooth muscle 64,65 cells.

Our study of the patients with retinopathy had mean serum lipid profiles: Total cholesterol 189.56, LDL-cholesterol 127.43, HDL-cholesterol 38.84, and LDL: HDL-cholesterol ratio of 3.30, and that of Serum Triglyceridesbeing 129.26. And those with normal fundus had mean serum lipid levels as follows: Total cholesterol 188.28, LDL-cholesterol 119.00, HDL-cholesterol38.63, LDL: HDL-cholesterol ratio 3.14, and that of Serum Triglycerides being 37.87.

In general, the association of serum total cholesterol levels was not significant. All the inter & intragroup comparisons were also statistically significant except for those of average Vs. Grade I retinopathy (P,0.96) & grade II Vs. Grade III (<0.53). We discovered an important link between LDL-Cholesterol serum& the severity of the retinopathy (p=0.036). The intergroup comparison of no retinopathy & Grade I, II, III retinopathy groups, and Grade I Vs. ' intragroup comparisons. Grade II, Grade I Vs. Grade III; Grade II Vs. Grade III also showed a statistically significant association except for the average Vs. GradeI category. The mean serum HDL-Cholesterol values for the retinopathy group were 38.84& that for the no retinopathy group was 38.63. There was no association between the serum HDL-Cholesterol & retinopathy (P=0.801). Although the overall association of serum triglycerides was found to be significant with retinopathy (p=0.04).

The correlation between serum lipid parameters&hypertensive retinopathy prevalence has been shown. It is possible to consider dyslipidemia as a significant risk factor for the occurrence &seriousness of retinopathy and other failures of the final organ. Multi-organ intervention in hypertension is a norm rather than an anomaly, considering that injury in various areas does not seem to be either synchronous or standardized. A recommendation for ophthalmologists to review lipid parameters in patients with hypertensive retinopathy is our findings' therapeutic effect, which may better classify patients with life-threatening cerebrovascular and carotid artery conditions. Vision safety can be an additional driving factor in reducing serum lipid levels in patients with high blood pressure at elevated levels.

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