The hidden heart risk in India’s ‘healthy-looking’ adults

At Nair Hospital in central Mumbai, the warning did not come only from patients seeking treatment. It came from the people who had walked in with them.In September 2022, the BMC-run Topiwala National Medical College and BYL Nair Charitable Hospital, one of Mumbai’s major civic teaching hospitals, began asking relatives accompanying patients a basic question: would they like to get their blood sugar and blood pressure checked? Most were not there as patients.

Many considered themselves healthy. Many had no symptoms.But the free walk-in screening at the hospital’s non-communicable disease corner revealed what doctors say is now a familiar urban Indian risk: a worryingly large number of people who are pre-diabetic or suffer from hypertension and are blissfully unaware of their condition.Prediabetes is a condition where blood sugar levels are higher than normal but not yet high enough to be classified as Type 2 diabetes.

Hypertension, commonly known as high blood pressure, is a chronic condition in which the force of blood against your artery walls is consistently too high.Over time, hypertension forces the heart to work harder to pump blood and significantly increases the long-term risk of heart disease, stroke, and kidney failure.Diabetes, as is well known, damages blood vessels and nerves and increases risk of cardiovascular disease and kidney failure.

The numbers that the random testing at Nair Hospital recorded were startling.

Doctors say the findings offer one explanation for a question many families and hospitals are now forced to confront: why do apparently healthy Indians, including those in their 30s and 40s, suffer sudden cardiac events? The answer, they say, often lies in years of undetected metabolic damage.What the screening foundThe initiative was meant to assess whether people who see themselves as healthy actually know their blood sugar and blood pressure status.

The results suggest a large awareness gap.According to the hospital data, 9,274 people screened positive for elevated random blood sugar, 7,238 screened positive for hypertension-range blood pressure, and 2,396 screened positive for both.For the screening programme, diabetes mellitus screening positivity was identified by a random capillary blood glucose level exceeding 140 mg/dL.A systolic blood pressure of 140 mm Hg or higher, or diastolic blood pressure of 90 mm Hg or higher, was considered a positive screening result for hypertension.A positive screen does not mean a confirmed diagnosis. It means the person needs further evaluation. Those with elevated blood sugar were advised to undergo confirmatory tests, including HbA1c, while those with raised blood pressure were advised to repeat measurements. Many continued monitoring their blood pressure over the following five days. These follow-up readings will form part of the confirmed dataset, which is currently under analysis.The overlap matters because high blood sugar and high blood pressure together sharply raise the risk of heart attacks, strokes, kidney disease and damage to blood vessels.Doctors call both conditions silent risks. A person can feel normal, work normally and have no pain, while damage is already building inside the body.Among those with abnormal blood sugar readings, nearly two-thirds — around 66% — were in the prediabetes range used by the screening programme, with random blood sugar levels between 140 and 199 mg/dL.

A reading of 200 mg/dL or higher was treated as being in the diabetes range and required confirmatory evaluation.Similarly, more than 68% of those with high blood pressure were in the early stage of hypertension, when blood pressure begins to rise above the normal range — typically 140–159 mm Hg systolic or 90–99 mm Hg diastolic — but individuals often have no symptoms and may feel completely healthy.Why waist size mattersThe findings reflect a larger national trend. Across India, non-communicable diseases are rising not only in numbers but also in how early they appear.

More people are developing high blood sugar, high blood pressure, obesity and abdominal fat in their 30s and 40s.Dr Rujuta Hadaye, professor and head of community medicine at Nair Hospital, said the findings are deeply concerning. “More than half of the people we screened were either overweight or obese, which is much higher than what we usually see. What is even more worrying is that many people who appear to have a normal weight are actually carrying excess fat around the abdomen,” she said.“This hidden fat — what we call normal-weight abdominal obesity — was seen in over 40% of individuals and is strongly linked to insulin resistance, high blood pressure and future risk of heart disease,” she added.Abdominal obesity is not just about weight. It refers to excess fat around the waist, particularly visceral fat, which surrounds internal organs. This kind of fat is metabolically active: it can worsen insulin resistance, raise blood pressure, disturb cholesterol levels and increase inflammation.

That is why someone with a “normal” body weight can still carry high metabolic risk if their waist circumference is high.Although the study did not directly capture dietary habits, experts say the high levels of obesity and abdominal fat are consistent with unhealthy diets, high carbohydrate intake, long sitting hours and other lifestyle patterns common in urban settings.The screening also found that nearly 69% of participants reported meeting recommended physical activity levels, benchmarked against the World Health Organization guideline of at least 150 minutes of moderate activity a week.

However, 21.5% were completely sedentary. Substance use, particularly alcohol, was higher among men, adding to the overall risk burden.Men showed a higher screening burdenThe screening covered 30,054 men and 25,946 women. Among men, 4,996 screened positive for elevated blood sugar, 4,498 screened positive for hypertension-range blood pressure, and 1,477 screened positive for both. Among women, 4,278 screened positive for elevated blood sugar, 2,740 screened positive for hypertension-range blood pressure, and 919 screened positive for both.Overall, the data suggests that elevated blood sugar was more commonly detected than high blood pressure, while a significant number had both risk factors at the same time.How high sugar damages the heart“The study shows diabetes has overtaken hypertension in prevalence. High blood sugar damages blood vessels early, accelerating plaque buildup and increasing the risk of heart attacks — even in people in their 30s and 40s,” said Dr Ajay Chaurasia, head of the cardiology department at B Y L Nair Hospital.Plaque buildup refers to the accumulation of fat, cholesterol and other substances inside blood vessels. As plaque grows, arteries narrow and blood flow to the heart can reduce. If a plaque ruptures and a clot forms, it can suddenly block blood supply and trigger a heart attack.“Heart attacks and strokes do not occur overnight. They are often the result of years of silent damage caused by conditions like high blood sugar and high blood pressure.

What makes this study particularly worrying is that it was based on random screening — meaning many individuals were likely unaware of their condition,” Dr Chaurasia said.In simple terms, a large section of seemingly healthy people may already be on the path to serious heart disease, he added. “It is the visible outcome of an invisible epidemic of metabolic disease. Unless addressed early, today’s ‘healthy-looking’ population could become tomorrow’s cardiac emergency,” Dr Chaurasia said.The hospital has advised both newly diagnosed individuals and those with a known history of diabetes or hypertension to undergo a detailed evaluation. “This is important to assess whether any silent damage has already occurred to vital organs, especially the heart, and to initiate timely management,” said Dr Shailesh Mohite, dean of the hospital.A national warningIndia’s larger numbers are already alarming. The ICMR-INDIAB survey estimated that India had 101 million people with diabetes and 136 million people with prediabetes in 2021.

Prediabetes prevalence was estimated at 15.3% nationally.The ICMR-INDIAB study found that while diabetes, hypertension, obesity and dyslipidaemia were more common in urban populations, prediabetes showed no consistent urban-rural difference. Researchers noted that the diabetes burden is stabilising in more developed states but continues to rise in several others, underscoring the need for state-specific interventions.“Considering the current prevalence of prediabetes, there can be a tsunami of type 2 diabetes in the next two decades in India,” said Dr Vyankatesh Shivane, diabetologist and metabolic physician, department of endocrinology, Jaslok Hospital & Research Centre, Mumbai.He said much greater attention is needed on childhood obesity, healthy lifestyle education in schools and physical activity among adults. Young professionals spending long hours on computers, laptops and phones should take stretching breaks of five to 10 minutes every two hours, he said.“The government needs to implement universal screening for diabetes and prediabetes for everyone above 25 years. This will help to detect the cases early and manage them,” Dr Shivane said.Type 2 diabetes is the most common form of diabetes. It develops when the body becomes resistant to insulin or does not make enough insulin to keep blood sugar in a healthy range. It is strongly linked to family history, excess weight, abdominal fat, low physical activity and diet, though Indians can develop it even at lower body weights than many Western populations.Dr Anil Bhoraskar, senior diabetologist at SL Raheja Hospital, Mahim, and secretary, Diabetic Association of India, said Indians face a particular metabolic vulnerability.“In India, the prevalence of diabetes, heart disease and cancer is high partly because of our genetic susceptibility. However, what is equally concerning is the ‘thin-fat’ body composition seen in many Indians — where even individuals with a normal BMI can have high waist circumference due to excess visceral fat.“This hidden fat, largely driven by poor dietary patterns from a young age, increases the risk of metabolic diseases. Unlike metabolically active ‘brown fat’, most of this is ‘white fat’, which contributes to insulin resistance and cardiovascular risk. The issue is not just sugar intake but the quality of fats in the diet. Additionally, nearly 60% of our diet comes from carbohydrates, which ideally should be reduced to around 45% to improve metabolic health,” Dr Bhoraskar said.The Nair Hospital screening does not prove that every person with a raised reading already has established diabetes, hypertension or heart disease. But it does show why doctors are pushing for earlier checks. For many Indians, the first sign of high blood sugar or high blood pressure should not be a heart attack.