Microalbuminuria, a urine albumin excretion ranging from 30 to 300 mg/day, is described as a marker of endothelial dysfunction [6, 12,13,14], and glomerular hyperfiltration , and is correlated with the structural and functional integrity of the vasculature . Subtle changes in albumin excretion reflect generalized vascular processes and highlight the complex association between chronic kidney disease and cardiovascular disease . Microalbuminuria is a known risk factor for metabolic syndrome , cardiovascular disease , and peripheral arterial disease . It is associated with cardiovascular morbidity and mortality in patients presenting with hypertension , in individuals presenting with or without diabetes , or with end-stage renal disease in individuals with an adverse cardiovascular risk profile [12, 18]. It is common in the general population, especially in patients with DM or HBP .
However, studies indicate that lower levels of UACR, previously considered within the normal range, associate LGA with cardiovascular morbidity and mortality in the general population . Urine albumin excretion predicts blood pressure progression in non-diabetic and non-hypertensive individuals incrementally in relation to established risk factors and at levels well below the conventional threshold for microalbuminuria . In The Framingham Heart Study, which was carried out with middle-aged, non-hypertensive, and non-diabetic individuals, urine excretion of LGA predicted the development of cardiovascular diseases [5, 18], challenging the indication of the limit for albumin excretion considered normal5 and suggesting that this level, in the general population, is much lower .
The results of this study demonstrate a significant association between LGA and 10-year CVD risk in a sample of hypertensive and/or diabetic patients assisted by PHC. Several other studies associate LGA with increased risk of all-cause cardiovascular disease [12, 13, 18,19,20,21], including apparently healthy individuals presenting no DM or HBP . A study carried out with a nationally representative sample of 9736 adult Koreans associated albuminuria within the normal range with metabolic syndrome . A study carried out with 1341 middle-aged and elderly Chinese adults, who were normotensive and euglycemic, presenting normal UACR ratios, suggested the existence of a contribution of LGA to the risk of atherosclerosis . Another study carried out with 760 Chinese participants aged from 29 to 76 years, presenting type 2 DM and normoalbuminuria, has demonstrated a significant association between LGA and increased thickness of the carotid intima-media layer . UACR was associated with subclinical left ventricular diastolic dysfunction and left ventricular remodeling in patients presenting with and without type 2 DM .
There is evidence suggesting that LGA, below the microalbuminuria threshold, is associated with an increased prevalence of metabolic syndrome and its components , systemic vascular dysfunction, and cardiovascular mortality . LGA is prevalent in patients presenting hypertension and is associated with an unfavorable outcome , it may identify individuals who are more likely to develop HBP , it may also be used to detect early cardiovascular disease in patients presenting type 2 DM , it may contribute to the risk of carotid atherosclerosis , and it may also be used to independently predict the incidence of cardiovascular disease and mortality in apparently healthy individuals with optimal blood pressure, without diabetes, and in the general population . LGA has also been associated with left ventricular hypertrophy and left ventricular diastolic dysfunction in hypertensive patients , and is a potentially important risk factor for ischemic stroke, especially for the lacunar subtype .
LGA may also be an important marker of subclinical cardiovascular damage  and be used as an early marker for the detection of atherosclerosis in patients presenting type 2 DM , for the detection of peripheral arterial disease in diabetic patients , as well as being useful as an early biomarker for cardiovascular risk and mortality [18, 23, 24]. LGA also seems to be a more important determinant in the early stages of chronic kidney disease than glomerular filtration rate .
Finally, there may be some clinical relevance for albuminuria measurement tests, which are simple , widely available commercially [14, 25], inexpensive, and reliable . These are interactive tests, which are used in combination as a preliminary instrument in the diagnosis and prognosis of chronic kidney disease , and also offer an evaluation of the risk of endothelial dysfunction, in order to provide screening for diseases, comparable to the role of blood pressure and lipids , in addition to predicting adverse outcomes, including mortality . Therefore, these tests should be regularly performed in the elderly, in patients presenting DM, HBP, and cardiovascular diseases .
In addition to the results considered and consistent with data already described in the literature, other factors that make this study relevant are the representative sample and the pioneering approach in the city and region. However, the sample size makes the results of the present study more exploratory in nature and, ideally, should constitute a springboard for a larger and more representative study. Other limitations of the study were related to the failure to use the 24-hour urine collection technique when obtaining these samples and also to the lack of comparison of data in individuals without high blood pressure and diabetes.
Therefore, the results of the present study suggest that the screening for LGA can be a potential ally in preventive work in the Family Health Strategies and it requires a multidisciplinary approach, making its use necessary as an instrument to stratify hypertensive and diabetic patients assisted in Primary Health Care units. Moreover, it highlights the need for the development of effective public policies and the development of protocols that can be effective and put into practice by frontline healthcare providers working in the Brazilian Unified Health System.
It is concluded that LGA was prevalent and significantly associated with cardiovascular risk in patients diagnosed with HBP and/or DM, proving to be an important indicator to estimate the 10-year risk of cardiovascular event, with potential for routine use in PHC.