Diabetic Foot Ulcers: A Neglected Complication of Lipodystrophy

Endothelial dysfunction in vascular complications of diabetes: a comprehensive review of mechanisms and implications

Diabetic vascular complications are prevalent and severe among diabetic patients, profoundly affecting both their quality of life and long-term prospects. These complications can be classified into macrovascular and microvascular complications. Under the impact of risk factors such as elevated blood glucose, blood pressure, and cholesterol lipids, the vascular endothelium undergoes endothelial dysfunction, characterized by increased inflammation and oxidative stress, decreased NO biosynthesis, endothelial-mesenchymal transition, senescence, and even cell death. These processes will ultimately lead to macrovascular and microvascular diseases, with macrovascular diseases mainly characterized by atherosclerosis (AS) and microvascular diseases mainly characterized by thickening of the basement membrane. It further indicates a primary contributor to the elevated morbidity and mortality observed in individuals with diabetes. In this review, we will delve into the intricate mechanisms that drive endothelial dysfunction during diabetes progression and its associated vascular complications. Furthermore, we will outline various pharmacotherapies targeting diabetic endothelial dysfunction in the hope of accelerating effective therapeutic drug discovery for early control of diabetes and its vascular complications.

Clinical features of generalized lipodystrophy in Turkey: A cohort analysis

AIM

To describe the Turkish generalized lipodystrophy (GL) cohort with the frequency of each complication and the death rate during the period of the follow-up.

METHODS

This study reports on 72 patients with GL (47 families) registered at different centres in Turkey that cover all regions of the country. The mean ± SD follow-up was 86 ± 78 months.

RESULTS

The Kaplan-Meier estimate of the median time to diagnosis of diabetes and/or prediabetes was 16 years. Hyperglycaemia was not controlled in 37 of 45 patients (82.2%) with diabetes. Hypertriglyceridaemia developed in 65 patients (90.3%). The Kaplan-Meier estimate of the median time to diagnosis of hypertriglyceridaemia was 14 years. Hypertriglyceridaemia was severe (≥ 500 mg/dl) in 38 patients (52.8%). Seven (9.7%) patients suffered from pancreatitis. The Kaplan-Meier estimate of the median time to diagnosis of hepatic steatosis was 15 years. Liver disease progressed to cirrhosis in nine patients (12.5%). Liver disease was more severe in congenital lipodystrophy type 2 (CGL2). Proteinuric chronic kidney disease (CKD) developed in 32 patients (44.4%) and cardiac disease in 23 patients (31.9%). Kaplan-Meier estimates of the median time to diagnosis of CKD and cardiac disease were 25 and 45 years, respectively. Females appeared to have a more severe metabolic disease, with an earlier onset of metabolic abnormalities. Ten patients died during the follow-up period. Causes of death were end-stage renal disease, sepsis (because of recurrent intestinal perforations, coronavirus disease, diabetic foot infection and following coronary artery bypass graft surgery), myocardial infarction, heart failure because of dilated cardiomyopathy, stroke, liver complications and angiosarcoma.

CONCLUSIONS

Standard treatment approaches have only a limited impact and do not prevent the development of severe metabolic abnormalities and early onset of organ complications in GL.

Complications of lipodystrophy syndromes

Lipodystrophy syndromes are rare complex multisystem disorders caused by generalized or partial lack of adipose tissue. Adipose tissue dysfunction in lipodystrophy is associated with leptin deficiency. Lipodystrophy leads to severe metabolic problems. These abnormalities include, but are not limited to, insulin-resistant diabetes, severe hypertriglyceridemia, and lipid accumulation in ectopic organs such as the liver, and are associated with end-organ complications. Metabolic abnormalities can be present at the time of diagnosis or may develop over time as the disease progresses. In addition to metabolic abnormalities, subtype-specific presentations due to underlying molecular etiology in genetic forms and autoimmunity in acquired forms contribute to severe morbidity in lipodystrophy.

Risk factors for diabetic foot ulcers in metreleptin naïve patients with lipodystrophy

AIM

Patients with lipodystrophy are at high risk for chronic complications of diabetes. Recently, we have reported 18 diabetic foot ulcer episodes in 9 subjects with lipodystrophy. This current study aims to determine risk factors associated with foot ulcer development in this rare disease population.

METHODS

Ninety metreleptin naïve patients with diabetes registered in our national lipodystrophy database were included in this observational retrospective cohort study (9 with and 81 without foot ulcers).

RESULTS

Patients with lipodystrophy developing foot ulcers had longer diabetes duration (p = 0.007), longer time since lipodystrophy diagnosis (p = 0.008), and higher HbA1c levels (p = 0.041). Insulin use was more prevalent (p = 0.003). The time from diagnosis of diabetes to first foot ulcer was shorter for patients with generalized lipodystrophy compared to partial lipodystrophy (p = 0.036). Retinopathy (p < 0.001), neuropathy (p < 0.001), peripheral artery disease (p = 0.001), and kidney failure (p = 0.003) were more commonly detected in patients with foot ulcers. Patients with foot ulcers tended to have lower leptin levels (p = 0.052). Multiple logistic regression estimated significant associations between foot ulcers and generalized lipodystrophy (OR: 40.81, 95% CI: 3.31-503.93, p = 0.004), long-term diabetes (≥ 15 years; OR: 27.07, 95% CI: 2.97-246.39, p = 0.003), and decreased eGFR (OR: 13.35, 95% CI: 1.96-90.67, p = 0.008).

CONCLUSIONS

Our study identified several clinical factors associated with foot ulceration among patients with lipodystrophy and diabetes. Preventive measures and effective treatment of metabolic consequences of lipodystrophy are essential to prevent the occurrence of foot ulcers in these high-risk individuals.

Exercise Increases Bone in SEIPIN Deficient Lipodystrophy, Despite Low Marrow Adiposity

Exercise, typically beneficial for skeletal health, has not yet been studied in lipodystrophy, a condition characterized by paucity of white adipose tissue, with eventual diabetes, and steatosis. We applied a mouse model of global deficiency of Bscl2 (SEIPIN), required for lipid droplet formation. Male twelve-week-old B6 knockouts (KO) and wild type (WT) littermates were assigned six-weeks of voluntary, running exercise (E) versus non-exercise (N=5-8). KO weighed 14% less than WT (p=0.01) and exhibited an absence of epididymal adipose tissue; KO liver Plin1 via qPCR was 9-fold that of WT (p=0.04), consistent with steatosis. Bone marrow adipose tissue (BMAT), unlike white adipose, was measurable, although 40.5% lower in KO vs WT (p=0.0003) via 9.4T MRI/advanced image analysis. SEIPIN ablation's most notable effect marrow adiposity was in the proximal femoral diaphysis (-56% KO vs WT, p=0.005), with relative preservation in KO-distal-femur. Bone via μCT was preserved in SEIPIN KO, though some quality parameters were attenuated. Running distance, speed, and time were comparable in KO and WT. Exercise reduced weight (-24% WT-E vs WT p<0.001) but not in KO. Notably, exercise increased trabecular BV/TV in both (+31%, KO-E vs KO, p=0.004; +14%, WT-E vs WT, p=0.006). The presence and distribution of BMAT in SEIPIN KO, though lower than WT, is unexpected and points to a uniqueness of this depot. That trabecular bone increases were achievable in both KO and WT, despite a difference in BMAT quantity/distribution, points to potential metabolic flexibility during exercise-induced skeletal anabolism.