The global burden of diabetes mellitus and its chronic complications—including premature atherosclerotic cardiovascular disease and microvascular impairments such as nephropathy, retinopathy, and neuropathy—highlights the need for improved strategies for the early identification of individuals at risk of carbohydrate metabolism disorders. Growing evidence suggests that alterations in the microcirculatory bed occur concomitantly with, or may even precede, the development of cardiovascular disease. The eye, owing to its transparent anatomical structures, provides a unique opportunity for the in vivo assessment of microvascular changes and offers valuable insights into other vascular territories, serving as a potential “window” into cardiometabolic disorders. Recent advances in microcirculation imaging have enabled detailed, non-invasive evaluation of the retinal microvasculature. Techniques such as scanning laser Doppler flowmetry (SLDF), adaptive optics (AO), optical coherence tomography angiography (OCTA), and laser speckle flowgraphy (LSFG) allow for quantitative assessment of the retinal microvascular bed, demonstrating partial correlation with invasive measures of vascular function and sensitivity to therapeutic interventions. The integration of these imaging modalities into clinical and research settings may facilitate the early detection of microvascular dysfunction, improve risk stratification, and support the monitoring of disease progression and treatment efficacy in patients with carbohydrate metabolism disorders. Therefore, this review aims to summarize the current evidence on retinal microvascular alterations in carbohydrate metabolism disorders assessed using advanced imaging techniques, focusing primarily on early, subclinical retinal changes that precede the onset of diabetic retinopathy.

Background: Sarcoidosis is a heterogeneous, multisystem inflammatory disease with an unpredictable clinical course and limited prognostic markers. Increasing attention has focused on nutritional and metabolic factors—particularly obesity, body composition, and calcium–vitamin D metabolism—as potentially modifiable elements associated with disease development and clinical phenotype. However, the available literature remains fragmented and methodologically heterogeneous. Objective: To systematically map current evidence on the relationship between nutritional status and the development, clinical course, and prognosis of sarcoidosis, and to identify key gaps requiring further research. Methods: A scoping review was conducted in accordance with the Joanna Briggs Institute methodology and the PRISMA-ScR guidelines. PubMed, Scopus, Web of Science, Cochrane Library, EBSCO, and Google Scholar were searched for studies published between 2015 and 2025. Eligible studies included adult patients with sarcoidosis and addressed nutritional status broadly defined, encompassing anthropometric measures, body composition, immunonutritional indices, nutrition-related biomarkers, dietary factors, and supplementation practices. Due to substantial heterogeneity in exposure definitions and outcome measures, no quantitative synthesis or formal methodological quality appraisal was performed. Results: Eighteen studies, predominantly observational, were included. The most consistent findings concerned anthropometric parameters, with overweight and obesity showing the strongest association with an increased risk of sarcoidosis and, in selected studies, with reduced exercise capacity and greater disease burden. Evidence linking nutritional status to prognosis was indirect, while direct data on sarcoidosis-specific survival were lacking. Disturbances in calcium–vitamin D metabolism were frequent and clinically relevant, particularly in the context of supplementation-related hypercalcemia. Conclusions: Current evidence suggests that nutritional status—particularly excess body weight—and selected metabolic and immunonutritional factors are associated with sarcoidosis. However, given the largely observational nature of the available data and the lack of formal assessment of methodological quality, these results should be interpreted as association mapping and hypothesis generation rather than as evidence of causality. Well-designed prospective and interventional studies using standardized nutritional assessment tools and clinically relevant endpoints are needed to clarify the role of nutritional factors in sarcoidosis.