Diabetes and chronic kidney disease damage the heart. The left ventricle becomes stiff, leading to left ventricular diastolic dysfunction. As a result, the heart cannot fill with blood between beats. Left ventricular diastolic dysfunction affects a large proportion of type 2 diabetic patients. This often leads to mortality due to diastolic heart failure.
How does diabetic nephropathy cause heart stiffness leading to left ventricular diastolic dysfunction? What can we do to monitor the problem among Indian diabetic patients?
Recently, doctors at Santosh Medical College Gaziabad, Uttar Pradesh started investigating.
They inducted one hundred and one diabetic individuals of both sexes aged above 35 years. They followed the 2021 American Diabetes Association guidelines to confirm the diagnosis of diabetes. The researchers excluded individuals having heart and liver disease, thyroid problems, any concurrent illness and pregnant females. They also excluded patients with severe kidney problems, poor heart ultrasound images, high alcohol use, and active infections.
The researchers recorded biochemical parameters and demographic details such as age, gender, comorbid conditions, smoking history, and BMI for baseline analysis. Urine albumin and serum creatinine levels were measured. Based on albumin levels, patients were categorised into normoalbuminuric, microalbuminuria and macroalbuminuria cases.
To observe the flow of blood across the mitral valve during diastole, the heart’s relaxation phase, the researchers recorded the echocardiogram of the volunteers. The echocardiogram shows two waves – the E wave representing early diastolic filling and the A wave which is related to atrial contraction on the doppler.
Based on the E/A ratio, the researchers classified diastolic dysfunction into three grades. If the ratio is less than one, it means that theA wave becomes longer. Due to the stiffness of the left ventricle, relaxation is slow and early blood filling is reduced.
If the E wave is bigger or if E/A is greater than one, the disease has progressed: due to stiffness in the left ventricle, the left atrium pressure is increased.
If E/A is greater than two, or the E wave looks taller than the A wave, it means that left atrium pressure is elevated. The left ventricle has become very stiff and the filling is restrictive. Hence, early filling is rapid but then it stops.
The researchers used tissue Doppler imaging to measure the speed of the heart muscle moving at the mitral ring, a proxy measure for how hard the heart works to fill with blood.
They calculated the ratio between the E wave and the speed of the heart muscle at the mitral ring. Cases where the ratio is more than 15 have higher left ventricular end‑diastolic pressure. If it is more than nine, the risk of cardiovascular events and all-cause mortality is high.
Calculating using these formulae, the researchers determined that, out of 101 diabetic patients, 58 had diastolic dysfunction and 43 showed normal heart relaxation. Diastolic dysfunction was greater among males than among females.Though those with longer duration of diabetes and who were older showed higher diastolic dysfunction, the association was not significant.
Lipid profile analysis showed significantly elevated levels of low-density lipoprotein among patients with diastolic dysfunction compared to those without diastolic dysfunction.
Is there a correlation between albuminuria and left ventricle diastolic dysfunction?
The researchers examined the data and found that albuminuria and left ventricle diastolic dysfunction were significantly correlated. The higher the amount of albumin in urine, the greater the diastolic dysfunction. Reduced renal function seemed to exacerbate diastolic dysfunction. In cases where the estimated glomerular filtration rate was lower, there was a greater incidence of left ventricle diastolic dysfunction.
These correlations help clinicians suggest testing of heart conditions to those diagnosed with diabetic nephropathy.
Correlations, of course, do not suggest causation. Both diabetic nephropathy and diabetes induced cardiovascular diseases may have common causative mechanisms.
We hope to bring you news on further research on the molecular mechanisms involved in complications due to diabetes soon.
Annals of African Medicine, 25:1140-5 (2026);
DOI: 10.4103/aam.aam_267_25
Reported by Umme Najiya Mahwish
Freelance science writer, Hyderabad
This report was written in a workshop for capacity building of PhD scholars
organised by scienceandmediaworkshops.
The reports on this site are free-to-use for Indian media houses.
STEAMindiaReports: steaming hot science news you can use.
STEAMindiaReports 
Leave a comment