Diabetic nephropathy in the elderly

　　The occurrence and development of diabetic nephropathy in the elderly are due to the synergistic effects of multiple factors. Disordered glucose metabolism, abnormal renal hemodynamics, various active cytokines, and genetic factors all play an important role in the occurrence of the disease.

　　Diabetic nephropathy in the elderly can lead to a variety of complications, generally including the following points:

　　1. Proteinuria

　　The onset of nephrotic syndrome is due to increased glomerular filtration pressure and changes in the charge on the filtration membrane, resulting in only trace amounts of albumin in the urine, which is selective proteinuria. There is no increase in globulin, and this condition can last for many years. With the enlargement of the glomerular basement membrane filtration pores, large molecular substances can pass through, leading to non-selective clinical proteinuria. As the disease progresses further, urinary protein levels gradually become persistent and severe. If urinary protein exceeds 3 grams per day, it is an adverse prognostic sign.

　　2. Edema

　　Early diabetic nephropathy patients generally do not have edema. A few patients may have mild edema before the plasma protein decreases. When the 24-hour urine protein exceeds 3 grams, edema will appear. Significant general edema is only seen in patients with rapidly progressing diabetic nephropathy.

　　3. Hypertension

　　Hypertension is common in diabetic nephropathy patients. Severe kidney disease often accompanies hypertension, and hypertension can accelerate the progression and deterioration of diabetic nephropathy, so effective control of hypertension is very important.

　　4. Anemia

　　Diabetic patients with significant azotemia may have mild to moderate anemia, which is ineffective with iron treatment. Anemia is caused by impaired erythropoiesis and may be related to long-term protein-restricted diet and azotemia.

　　The clinical manifestations of diabetic nephropathy (DN) in the elderly are very variable. In the early stage, there may be no clinical symptoms at all, while in the late stage, it can present with severe metabolic disorders and involvement of multiple systems in end-stage renal disease. The clinical manifestations mainly depend on the stage of DN disease and the degree of renal function decline in the patient.

　　1. Water metabolism disorder

　　As DN progresses, renal function is further damaged, and the concentration and dilution functions become worse. The urine specific gravity is fixed at 1.010～1.012, and the osmolality is about 280mOsm/kg, similar to plasma, known as isotonic urine. The patient's ability to regulate water has significantly decreased. If there is poor appetite, reduced water intake, acidosis increases the amplitude of respiration, more water is lost in the respiratory tract, and accompanied by diarrhea, vomiting, etc., it is easy to develop dehydration. The glomerular filtration rate decreases dramatically, and the urine output decreases day by day. Blood urea nitrogen and creatinine rise rapidly.

　　2. Electrolyte metabolic disturbance

　　Electrolyte disturbances are common in uremia caused by diabetic nephropathy (DN), which can occur with dehydration and edema. It can be single or a combination of several electrolyte metabolic disturbances. Depending on the different electrolyte disturbances, symptoms can include apathy, delayed reaction, weakness, muscle spasms, convulsions, fatigue, weakened or absent patellar reflexes, reduced bowel sounds, increased heart rate, weakened muscle strength, difficulty swallowing, drowsiness, atrioventricular or intraventricular conduction blockage, and even respiratory center paralysis, coma, or cardiac arrest and other symptoms.

　　3. Acidosis

　　Acidosis can be clinically manifested as deep breathing, decreased appetite, fatigue, weakened myocardial contraction, and blood pressure drop.

　　Diabetes is one of the common diseases in the elderly, and it is also an important trigger for diabetic nephropathy in the elderly. Therefore, everyone should learn the following preventive measures to reduce the incidence of the disease.

　　Primary prevention

　　Once diagnosed with diabetes or found to have impaired glucose tolerance (IGT), patients should actively seek treatment to correct the IGT status in the body, and prevent the occurrence of diabetes and microalbuminuria.

　　Secondary prevention

　　Diabetic patients should regularly undergo urine albumin, renal function (creatinine clearance), blood glucose, glycosylated hemoglobin, blood pressure, and fundus examination. Especially, the urine albumin test is beneficial for early diagnosis of diabetic nephropathy.

　　Three-level Prevention

　　The onset of clinical diabetic nephropathy is a sign of irreversible kidney damage. However, controlling glucose metabolism may help reduce the complications of diabetes (such as cardiovascular, neurological, retinal lesions, and infection) and may benefit to some extent in slowing the progression of kidney disease and improving the quality of life.

　　To make a clear diagnosis of the disease, it is generally necessary to take the following examination measures:

　　1. Microalbuminuria (UAER)

　　The variability of microalbuminuria (UAER) in the elderly is large, with elderly males (11.4±2.6) μg/min and females (8.2±2.2) μg/min.

　　2. Microalbuminuria

　　In 1988, Bernard et al. proposed that microalbuminuria can also be used as an early diagnostic indicator for elderly diabetic nephropathy. Some studies suggest that the excretion rate (TER) of transferrin (TRF) may be more sensitive than UAER, but it has not yet been officially recognized as an early diagnostic indicator.

　　3. Urinary Sialic Acid

　　Under normal circumstances, sialic acid is present on the basement membrane, and its charge barrier effect can prevent the leakage of small molecular albumin from the plasma. In the early stage of elderly diabetic nephropathy, the loss of sialic acid on the membrane destroys the charge barrier on the basement membrane, causing a significant increase in the excretion of sialic acid in urine. To some extent, the total urinary sialic acid can reflect the degree of kidney damage.

　　4. Exercise-Induced Test

　　Some diabetic patients cannot detect an increase in urinary protein excretion during quiet state or general activity, but the excretion of urinary protein increases after intense exercise, which is roughly equivalent to stage II of elderly diabetic nephropathy.

　　5. Early Changes in Glomerular Hemodynamic Parameters

　　Some early diagnostic indicators are mainly located in stage III, and some can reach stage II.

　　6. Early Indicators of Renal Tubular Dysfunction

　　The presence of albumin transferrin or NAG (N-acetyl-B-D-glucosaminidase) in urine suggests glomerular damage. However, the earlier hemodynamic changes characterized by glomerular hyperfiltration are functional changes of the glomerulus. Diabetic kidney disease not only manifests as glomerular damage but also reflects functional and实质性 damage to the renal tubules. Therefore, many studies explore early indicators of renal tubular damage for early diagnosis of elderly diabetic nephropathy.

　　7. Urinary Immunoglobulin G4 (IgG4) Excretion

　　IgG4 is one of the subclasses of plasma macromolecular immunoglobulin G4. Its presence in urine indicates a change in the pore size of the glomerular basement membrane. Therefore, detecting urine IgG4 levels can assist in the early diagnosis of elderly diabetic nephropathy.

　　8. Genetic Markers

　　In recent years, the role of genetic genes in the occurrence of elderly diabetic nephropathy has gradually received attention. It is currently believed that genetic factors play an important role in elderly diabetic nephropathy, or at least in the onset of some elderly diabetic nephropathy. Therefore, searching for genetic markers as predictors or assisting in the pre-diagnosis of elderly diabetic nephropathy has become a new hot topic.

　　A reasonable diet can effectively help patients recover better. For elderly diabetic nephropathy patients, you might as well try the following food therapy recipes, which are quite effective.

　　1. Euryale Seed and White Kernel of Ginkgo Porridge

　　Euryale seed 30 grams, white kernel of ginkgo 10 pieces, glutinous rice 30 grams. Shell the white kernel of ginkgo and cook it with euryale seed and glutinous rice in a pot with an appropriate amount of water, and cook into porridge. This recipe can be used to treat symptoms such as turbid urine and large amounts of protein excreted in urine.

　　2. Astragalus Porridge

　　Raw Astragalus 30-60 grams, glutinous rice 60 grams, tangerine peel powder 10 grams. First, decoct Astragalus for 15 minutes and remove the residue, then add glutinous rice to cook into porridge, and add tangerine peel powder after the porridge is cooked. This recipe can improve kidney function, eliminate proteinuria, and enhance physical fitness.

　　3. Black Bean Stewed Pork

　　Black beans 50 grams, lean meat 100 grams. First, place the pork in water, boil over high heat, remove the soup, then add water to cook the black beans together, and add appropriate seasonings after the meat and beans are soft. This recipe has the effects of tonifying the kidney, diuresis, and strengthening the spleen.

　　4. Goji Porridge

　　Goji berries 30 grams, glutinous rice 50 grams. Both are cooked with an appropriate amount of water into porridge, and eaten in the morning and evening. It has the effects of tonifying the kidney and spleen, and eliminating proteinuria.

　　If elderly diabetic nephropathy is not treated in a timely manner, serious consequences may occur. The following will introduce the common treatment methods for this disease.

　　1. Control Blood Sugar Levels

　　Early and active control of diabetes can restore kidney enlargement and reduce the elevated GFR to normal; for diabetic nephropathy stage III (microalbuminuria), intensive insulin therapy (continuous subcutaneous injection or multiple subcutaneous injections) can delay the progression of renal lesions, reduce urinary albumin; entering the clinical stage of diabetic nephropathy is a sign of irreversible kidney damage, but controlling glucose metabolism is beneficial to reduce the complications of diabetes (such as cardiovascular, neurological, retinal lesions, and infections, etc.), which may slow down the progression of renal lesions to some extent and be beneficial to improve the quality of life.

　　2. Antihypertensive Treatment

　　Hypertension accelerates the progression and deterioration of diabetic nephropathy, and long-term effective control of hypertension can delay the deterioration of renal function and help reduce proteinuria.

　　3. ACE Inhibitors

　　Angiotensin-converting enzyme (ACE) inhibitors are drugs recommended by most scholars in recent years for the treatment of diabetes, especially diabetic nephropathy.