The MR method was used in this study to investigate the causal relationship between T2DM and microalbumin using GWAS summary-level data. The primary analyses discovered evidence that genetically predicted T2DM was linked to microalbumin levels. It also suggested that microalbumin was related to the risk of T2DM.
Because of the increased proportion of microvascular complications associated with diabetes, such as diabetic nephropathy, the amount of diabetics with end-stage renal disease (ESRD) will rise sharply [23]. As a result, diabetes, particularly type 2 diabetes, is increasingly becoming the primary cause for patients to begin renal replacement treatment [24, 25].On average, 20–40% of diabetic people will have renal impairment [26]. Microalbuminuria is frequently the initial symptom of renal dysfunction, indicating the presence of overt nephropathy [27]. As a result, urine albumin measurement is frequently employed as a sensitive diagnostic and predictor of ESRD in diabetic patients [28]. Microalbuminuria and other risk factors linked with this illness must be monitored in order to avoid or postpone overt nephropathy [29]. The gold standard is microalbuminuria measurement in a 24-hour urine collection [30]. Furthermore, even within the normal range, the urinary microalbumin-to-urine creatinine ratio (UACR) is a significant predictor of diabetic nephropathy and an important risk factor for cardiovascular disease, and it shows endothelial dysfunction in DM [31, 32].
A recent study discovered that people with excessive urine microalbumin concentrations had a considerably greater risk of developing T2DM [33]. Furthermore, there were favorable relationships between microalbumin concentrations and various metabolic syndrome components, such as hypertension and hyperglycemia. Urinary microalbumin concentration increases of 10 mg/L were linked to a 10% increase in the incidence of T2DM [33]. Microalbumin levels below the threshold for microalbuminuria might substantially predict the risk of cardiometabolic problems [34]. The NHANES study discovered a connection among microalbuminuria and the possibility of hypertension and hyperglycemia [35]. The risk of developing T2DM was shown to be 1.90 (95% CI = 0.88–4.06) in an 11-year follow-up of 882 people aged 20 to 74, for those with microalbuminuria and 2.51 (95% CI = 1.08–5.87) for those with macroalbuminuria, respectively [36]. Microalbuminuria affects roughly 20–40% of diabetes individuals in various populations [37–39], This might be a precursor to diabetic nephropathy and other diabetes problems. To prevent future difficulties, adequate screening programs and tight control of modifiable risk factors are required. These outcomes matched the findings of the current investigation.
However, the fundamental processes linking urine microalbumin levels to the development of metabolic diseases are not entirely understood. Microalbuminuria is most commonly associated with vascular injury and endothelial dysfunction [40], culminating in type 2 diabetes [41]. On the other hand, the metabolic syndrome Endothelial permeability and intraglomerular capillary pressure may be increased by factors such abdominal obesity, hypertension, or hyperglycemia, which can cause kidney failure and microalbuminuria [42]. Thus, the mechanisms through which microalbumin has a negative impact on T2DM need to be investigated further.
Diabetic nephropathy can be used to investigate the mechanism of microalbumin's negative influence on T2DM. Despite the convoluted pathophysiology of diabetic nephropathy, podocyte damage has been recognized as being critical [43]. Podocyte structural alterations or destruction are linked to kidney injury, culminating in proteinuria and severe renal insufficiency, finally leading to diabetic nephropathy [44]. Furthermore, defective podocytes result in poor selective glomerular filtration and contribute to proteinuria development [45]. Meanwhile, the continuous hyperglycemia-induced formation of reactive oxygen species (ROS) would ultimately harm the antioxidant defense system, triggering oxidative stress (OS) and inflammatory reactions [46].
For many years, a role for inflammation in the development of T2DM has been hypothesized based on the reported associations between higher concentrations of inflammatory biomarkers such as CRP and interleukin-6 (IL-6) and T2DM risk [47]. A large MR research with CHD as the major outcome found that a functional variation causing defective signaling at the IL-6 receptor had a substantial influence on reduced T2DM risk [48]. However, in a comprehensive GWA meta-analysis, the same functional variation was found to be unrelated to T2DM risk [49]. Although the inflammatory theory in T2DM pathogenesis looks feasible, data from magnetic resonance imaging studies has yet to support it. However, bigger trials and investigations into additional inflammatory pathways may provide different results.
The application of the MR technique reduced inverse causality and confounding factors' influence with the findings, which may make them more credible than results from epidemiological studies. To the greatest of our knowledge, this study offers the first MR analysis of this problem. There must be some restrictions mentioned, though. First, we were incapable of identify whether individuals who participated in the GWAS used in the MR investigations coincided. Nonetheless, the F statistic has the potential to reduce the departure from participant overlap [50]. Second, using a rigorous various testing adjustment would have been overly conservative given the biologic validity and the cross statistical technique, potentially omitting possible causal factors for T2DM. As a result, We neglected to take repeated testing into consideration. Third, the findings of the research may not be generalizable to other ethnic groups because the most of GWAS volunteers were of European heritage.