High serum lipoprotein(a) levels in Korean type 2 diabetic patients with proliferative diabetic retinopathy

Correlation of periodontal inflamed surface area with glycated hemoglobin, interleukin-6 and lipoprotein(a) in type 2 diabetes with retinopathy

BACKGROUND

The two-way relationship between periodontitis and type 2 diabetes mellitus (T2DM) is well established. Prolonged hyperglycemia contributes to increased periodontal destruction and severe periodontitis, accentuating diabetic complications. An inflammatory link exists between diabetic retinopathy (DR) and periodontitis, but the studies regarding this association and the role of lipoprotein(a) [Lp(a)] and interleukin-6 (IL-6) in these conditions are scarce in the literature.

AIM

To determine the correlation of periodontal inflamed surface area (PISA) with glycated Hb (HbA1c), serum IL-6 and Lp(a) in T2DM subjects with retinopathy.

METHODS

This cross-sectional study comprised 40 T2DM subjects with DR and 40 T2DM subjects without DR. All subjects were assessed for periodontal parameters [bleeding on probing (BOP), probing pocket depth, clinical attachment loss (CAL), oral hygiene index-simplified, plaque index (PI) and PISA], and systemic parameters [HbA1c, fasting plasma glucose and postprandial plasma glucose, fasting lipid profile, serum IL-6 and serum Lp(a)].

RESULTS

The proportion of periodontitis in T2DM with and without DR was 47.5% and 27.5% respectively. Severity of periodontitis, CAL, PISA, IL-6 and Lp(a) were higher in T2DM with DR group compared to T2DM without DR group. Sig-nificant difference was observed in the mean percentage of sites with BOP between T2DM with DR (69%) and T2DM without DR (41%), but there was no significant difference in PI (P > 0.05). HbA1c was positively correlated with CAL (r = 0.351, P = 0.001), and PISA (r = 0.393, P ≤ 0.001) in study subjects. A positive correlation was found between PISA and IL-6 (r = 0.651, P < 0.0001); PISA and Lp(a) (r = 0.59, P < 0.001); CAL and IL-6 (r = 0.527, P < 0.0001) and CAL and Lp(a) (r = 0.631, P < 0.001) among study subjects.

CONCLUSION

Despite both groups having poor glycemic control and comparable plaque scores, the periodontal parameters were higher in DR as compared to T2DM without DR. Since a bidirectional link exists between periodontitis and DM, the presence of DR may have contributed to the severity of periodontal destruction and periodontitis may have influenced the progression of DR.

Lipoprotein (a) as a predictor of diabetic retinopathy in patients with type 2 diabetes: A systematic review

BACKGROUND

Lipoprotein a (LP(a)), an LDL-like lipoprotein, known as a risk factor for cardiovascular diseases, has a controversial association with diabetic retinopathy in patients with type 2 diabetes-the current systematic review aimed to critically assess the association between LP(a) and diabetic retinopathy.

METHODS

A systematic review of relevant studies was conducted after a thorough search in PubMed, Scopus, and Google Scholar electronic databases. We used English observational, case-control, and prospective cohort studies published up to August 2022, including type 2 diabetic patients as the population, diabetic retinopathy as the outcome, and LP(a) as the intervention.

RESULT

17 relevant studies, including 4688 patients with diabetes, were included in this systematic review. While in 13 studies, Lipoprotein(a) was recognized as a risk factor for diabetic retinopathy, only three studies reported no evidence of a relationship between the two. Also, another study showed a mixed outcome of the relationship between LP(a) and diabetic retinopathy.

CONCLUSION

High serum lipoprotein(a) in patients with type 2 diabetes is considered a risk factor for diabetic retinopathy. However, further large-scaled cohort studies are still required to validate this finding.

Clinical investigation of lipoprotein (a) levels in type 2 diabetics for cariovascular diseases prediction and prognosis

OBJECTIVES

We aimed to evaluate the levels of serum lipoprotein a, LP (a), in Jordanian patients with type 2 diabetes mellitus (DM); and to examine its relation to glycemic control, metabolic syndrome (MS) and duration of DM. The LP (a) is considered one of the independent risk factors for coronary artery disease (CAD) in the general population.

METHODS

Fasting blood samples were drawn from 51 diabetic patients with type 2 DM and 31 non-diabetic age and sex control subjects. Serum LP (a) was measured along with other parameters, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c) and glycosylated haemoglobin (HbA_1c). Correlation analyses were performed between LP (a) and the various variables measured.

RESULTS

LP (a) measurement showed a skewed distribution towards the lower levels in both groups. Mean LP (a) levels showed a statistically insignificant difference between the two groups. No correlations of LP (a) were observed with age, sex or body mass index (BMI). No correlations of LP (a) with LDL-c, HDL-c, TG, TC, MS, DM duration or HbA_1c were observed. The LP (a) serum levels were significantly higher in type 2 diabetic patients with retinopathy.

CONCLUSIONS

LP (a) serum levels are not increased in type 2 diabetic patients; so, LP (a) may not be a reliable marker for early therapeutic interventions in DM patients, even in high-risk for thrombosis groups.

General health of patients with diabetic macular edema-The LIPSIA study

Purpose

Cardiovascular risk factors such as hypertension or dyslipidemia can influence the incidence and progression of diabetic retinopathy (DR) and diabetic macular edema (DME). The aim of this study is to describe the comorbidities in patients with DME.

Methods

Prospective, monocentric observational study. Patients presenting for the treatment of DME received laboratory and clinical examinations including 24-hour blood pressure measurement.

Results

Seventy-five consecutive patients were included in the study. The mean age was 61.0 ± 14.5 years, and 83% had type 2 diabetes. The mean body mass index (BMI) was 32.8 ± 6.0 kg/m². Overweight (BMI ≥ 25 kg/m²) was present in 92% of all patients. HbA1c values were > 7.0% in 57%. Although 87% of the patients already received antihypertensive therapy, the blood pressure (BP) of 82% was still above the recommended target values of systolic < 140 mmHg and diastolic < 80 mmHg. An insufficient nocturnal fall of the systolic BP (< 10%, non-dipping or reverse dipping) was observed in 62%. In 83% of the patients the glomerular filtration rate was ≤ 90 ml/min/1.73m². Despite 65% of the cohort already receiving lipid-lowering therapy, LDL cholesterol was above the target value of 1.4 mmol/l in 93%. All patients had at least one cardiovascular risk factor in addition to diabetes (overweight, hypertension, insufficient nocturnal BP fall, dyslipidemia, or renal dysfunction) and 86% had ≥ 3 risk factors.

Conclusion

DME patients are characterized by highly prevalent cardiovascular risk factors that are poorly controlled. These comorbidities reduce the prognosis and negatively influence existing DR and DME. The data reveal an important opportunity for improving patient care by interaction of the ophthalmologist with the general practitioner and internal specialists for the detection and treatment of these conditions.

Association Between Serum Lipoprotein(a) and Diabetic Retinopathy in Han Chinese Patients With Type 2 Diabetes

CONTEXT

Contrasting observations have been made on the relationship between lipoprotein(a) [Lp(a)] concentration and diabetic retinopathy (DR) in patients with type 2 diabetes (T2D).

OBJECTIVE

To measure serum Lp(a) concentrations in patients with T2D to investigate whether Lp(a) affects risk for DR.

DESIGN AND PATIENTS

Serum Lp(a) was determined in 377 Han Chinese patients with T2D. Demographic and clinical information, including presence of DR and vision-threatening DR (VTDR), were collected on admission. The relationship between serum Lp(a) and DR or VTDR was evaluated using univariate and multivariate regression analyses.

RESULTS

Patients with DR or VTDR had significantly higher serum Lp(a) concentrations on admission (P < 0.001). The distribution across Lp(a) quartiles ranged from 11.7% (DR) and 4.3% (VTDR) in the first quartile to 47.9% (DR) and 19.1% (VTDR) in the fourth quartile (P for trend < 0.001). Multivariate logistic regression analysis adjusted for common DR and VTDR risk factors showed that the third and fourth Lp(a) quartiles were significantly associated with DR and VTDR compared with the first Lp(a) quartile (P < 0.001). The patient group with highest concentrations of both Lp(a) (fourth quartile) and hemoglobin A1c (≥7%) had an odds ratio for DR of 5.15 [95% confidence interval (CI), 2.78 to 9.55; P < 0.001] and for VTDR of 5.32 (95% CI, 2.92 to 10.15; P < 0.001) compared with patients with lower concentrations of both factors.

CONCLUSIONS

Lp(a) concentration was independently associated with DR in patients with T2D. More frequent retinal examinations should be recommended for patients with T2D and high Lp(a) concentrations.

Lipoprotein(a) serum levels in diabetic patients with retinopathy

BACKGROUND

Atherogenic lipoproteins, such as total cholesterol, LDL cholesterol, oxidized low density lipoprotein, and triglycerides, are associated with progression of retinopathy. Aim. To evaluate the relationship between lipoprotein(a) and retinopathy in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

We enrolled 145 diabetic consecutive patients (82 females, 63 males; mean age 66.8 ± 12 years, mean duration of diabetes 9.4 ± 6.8 years). Presence and severity of retinopathy were evaluated. Serum lipid profile, including Lp(a) level, was assessed.

RESULTS

High Lp(a) levels have been observed in 54 (78.3%) subjects and normal levels in 13 (18.85%) subjects as regards diabetic patients with retinopathy. Lp(a) levels were high in 15 subjects (21.75%) and normal in 63 subjects (91.35%) as regards patients without retinopathy.

CONCLUSIONS

Lp(a) levels are increased in a significant percentage of patients with retinopathy compared to diabetic patients without retinopathy. The impact of Lp(a) levels on diabetic retinopathy needs to be further investigated.

Lipoprotein(a) in type 2 diabetic subjects and its relationship to diabetic microvascular complications

AIM: To estimate the level of serum lipoprotein (a) [Lp (a)] in type 2 diabetes mellitus patients and to determine the relationship between Lp(a) in type 2 diabetes mellitus patients and micro-vascular complications.

METHODS: A cross sectional study was performed that enrolled 144 subjects with type 2 diabetes mellitus above the age of 25 years attending outpatient clinic of Government Medical College, Kozhikode. Lp(a) levels were measured quantitatively in venous samples using Turbidimetric Immunoassay in all subjects. Each patient was evaluated for micro vascular complications, namely diabetic retinopathy, nephropathy and neuropathy. The relationship between Lp(a) levels and the micro vascular complications was assessed by univariate analysis.

RESULTS: Mean age of cases was 53.93 ± 10.74 years with a male to female ratio of 1.3:1. Mean duration of diabetes was 9.53 ± 7.3 years. Abnormal Lp(a) levels (≥ 30 mg/dL) were observed in 38 (26.4%) diabetic subjects. Seventy-eight (54.16%) cases had diabetic nephropathy and significantly higher Lp(a) levels were found among these cases [Median 28.2 mg/dL (Interquartile range; IQR 24.4-33.5) vs 19.3 mg/dL (IQR 14.7-23.5); P < 0.05]. Retinopathy was present among 66 (45.13%) cases and peripheral neuropathy was detected among 54 (37.5%) cases. However, Lp(a) levels were not significantly different among those with or without retinopathy and neuropathy. Positive correlation was found between higher Lp(a) levels and duration of diabetes (r = 0.165, P < 0.05) but not with HbA1c values (r = – 0.083).

CONCLUSION: Abnormal Lp(a) levels were found among 26.4% of diabetic subjects. Patients with diabetic nephropathy had higher Lp(a) levels. No association was found between Lp(a) levels and diabetic retinopathy or neuropathy. Longer duration of diabetes correlated with higher Lp(a) levels.

Association between serum lipoprotein (a) level and progression of non-proliferative diabetic retinopathy in Type 2 diabetes

PURPOSE

To investigate independent risk factors related to the progression of non-proliferative diabetic retinopathy (NPDR) for Japanese Type 2 diabetic patients.

METHODS

One hundred and six patients with NPDR were followed up for 2 years. Diabetic retinopathy (DR) was determined by colour fundus photography. Multivariate logistic regression analysis was performed to assess variables independently associated with the progression of NPDR. Serum concentrations of novel risk factors for atherosclerotic vascular disease, including lipoprotein (a) [Lp(a)] and fibrinogen, were measured.

RESULTS

Thirty-three patients (31%) had progressed by two scale steps or more in 2 years. The progression of NPDR was significantly associated with HbA(1c) [odds ratio (OR) 2.12; 95% confidence interval (CI) 1.14-4.87], systolic blood pressure (OR 1.72; 95% CI 1.14-2.91), Lp(a) (OR 2.70; 95% CI 1.09-5.12) and fibrinogen (OR 1.68; 95% CI 1.03-3.08). Multivariate logistic regression analysis showed that HbA(1c) (OR 1.74; 95% CI 1.12-3.21) and Lp(a) level (OR 1.90; 95% CI 1.06-4.33) were significant and independent predictors of the progression of NPDR.

CONCLUSION

These data suggest that serum Lp(a) level is an independent risk factor for the progression of NPDR in Type 2 diabetes patients. We recommend that further prospective validation of our findings be undertaken to confirm these observations.

The role of lipids in the development of diabetic microvascular complications: implications for therapy

Dyslipidemia is a major factor responsible for coronary heart disease and its reduction decreases coronary risk in patients with diabetes mellitus. However, the association of dyslipidemia with microvascular complications and the effect of intervention with lipid-lowering therapy in diabetes have been less investigated. We present the systematic review of association and intervention studies pertaining to dyslipidemia and microvascular disease in diabetes and also review possible mechanisms. Dyslipidemia may cause or exacerbate diabetic retinopathy and nephropathy by alterations in the coagulation-fibrinolytic system, changes in membrane permeability, damage to endothelial cells and increased atherosclerosis. Hyperlipidemia is associated with faster decline in glomerular filtration rate and progression of albuminuria and nephropathy. Recent evidence also suggests a role of lipoprotein(a) in progression of retinopathy and nephropathy in patients with diabetes mellitus. Lipid-lowering therapy, using single agents or a combination of drugs may significantly benefit diabetic retinopathy and diabetic nephropathy. In particular, hydroxymethyl glutaryl coenzyme A reductase inhibitors may be effective in preventing or retarding the progression of microvascular complications because of their powerful lipid-lowering effects and other additional mechanisms. However, most of the data are based on short-term studies, and need to be ascertained in long-term studies. Until more specific guidelines are available, aggressive management of diabetic dyslipidemia, according to currently accepted guidelines, should be continued for the prevention of macrovascular disease which would also benefit microvascular complications.

The prevalence of retinopathy in an unselected population of type 2 diabetes patients from Arhus County, Denmark

PURPOSE

To determine the prevalence of diabetic retinopathy and the causes of visual impairment in an unselected population of type 2 diabetes patients, and to describe the risk factors for developing diabetic retinopathy in this population.

METHODS

A total of 10 851 type 2 diabetes patients were identified in the county of Arhus. A representative sample of 378 patients underwent a routine ocular examination, including fundus photography. Blood pressure and serum haemoglobin A1c, total cholesterol, high density lipoprotein cholesterol, triglyceride and apolipoprotein a were measured.

RESULTS

The prevalence of diabetic retinopathy in the type 2 diabetes population was 31.5%. In all, 2.9% had proliferative diabetic retinopathy and 5.3% had clinically significant macular oedema. Of the latter, 8/20 (40%) were newly identified and had not yet been laser-treated. There was a positive correlation between severity of retinopathy and duration of diabetes, HbA(1c), systolic blood pressure and treatment with insulin. None of the patients had social blindness (visual acuity < 0.1), but 15/378 (4.0%) had developed visual impairment (VA < 0.3).

CONCLUSION

The prevalence of diabetic retinopathy and visual impairment in this unselected type 2 diabetes population was lower than anticipated from the existing literature, and causes other than diabetic retinopathy contributed significantly to the occurrence of visual loss. A substantial number of the patients with vision-threatening diabetic maculopathy had not been referred for timely photocoagulation treatment.

The role of serum lipids in exudative diabetic maculopathy: is there a place for lipid lowering therapy?

Diabetic maculopathy is a common complication of diabetes mellitus, characterised by macular oedema and frequently accompanied by lipid exudation. It is the major cause of loss of vision from diabetic retinopathy. There is some evidence to implicate serum lipids in exudative maculopathy; cross-sectional studies suggest that higher serum lipid levels are found in patients with macular exudates, and prospective studies have shown an increased risk of exudative maculopathy if baseline cholesterol is higher. The treatment for diabetic maculopathy is laser photocoagulation of the pigment epithelium. With the advent of systemic lipid lowering therapy over the last decade, there may be potential for medical therapy also. There is some anecdotal evidence of the effect of lipid lowering agents (particularly statins) in reducing exudate, and a number of studies have shown that lipid lowering therapy may reduce macular exudates, but numbers in these trials are small. A randomised controlled trial is now required to investigate whether the use of systemic lipid lowering therapy is of benefit in patients with exudative maculopathy, even in the absence of dyslipidaemia.