Times of India
11 November 2010
By Pushpa Narayan

Study Shows That 20% Of City’s Population Suffers From A Kind Of Hypertension That Goes Undetected By The BP Apparatus
Two years ago, when doctors told 36–year–old Harish Mani, a senior manager in a private bank, that his blood pressure was normal, he decided he would not go on the stringent diet he had planned. Today, Harish has developed kidney disease and has been declared hypertensive. He is among the 20% of Chennai’s population that suffers from a disorder called ‘masked hypertension’.

In cases like his, hypertension is not detected by routine blood pressure measurement at the clinic. "The BP apparatus may not detect this. The disorder is masked and is hence not diagnosed. But they are at risk of stroke or a heart attack, similar to that of patients with sustained high blood pressure," says nephrologist Dr Rajan Ravichandran who, after a twoyear study, reported that nearly 20% of hypertension cases can go undetected.

Most doctors say ‘masked hypertension’ is as common as ‘white–coat’ hypertension. "For some people the blood pressure shoots up when they are at the doctor’s clinic. Otherwise they are normal. This kind of hypertension is called white–coat hypertension. In such cases, people can be needlessly put on drugs or warned about high salt intake. But masked hypertension is a case of dangerous under–diagnosis," said special physician Dr SN Narasingan, who heads the SNN Specialities Clinic in Alwarpet.

"Many such people don’t cut down on salt and realise there is a problem only when damages are caused to vital organs like heart, lungs, kidney or brain. I have several people coming to me who have developed heart disease due to high intake of salt and undiagnosed blood pressure," he said.

That’s what happened in the case of 47–year–old Gunasekaran K, who works as a medical representative for a leading pharmaceutical company. "I was speaking to a doctor about a new drug. Suddenly, the doctor felt there was a slur in my speech. He measured my blood pressure and found it as high as 210/140. I was immediately admitted. Nearly a year ago, I had undergone a master health check. My blood pressure was normal but the ECG was not normal. I did not know I was hypertensive then," he said.

Gunasekaran suffered a mild facial paralysis but has recovered now. "Doctors say I was purely lucky. I am now on a very strict diet and anti–hypertensive pills."

According to the World Health Organisation, 62% of all strokes and 49% of heart disease instances can be attributed to high BP. "It’s important to categorise people with high risk and do a 24–hour screening," says cardiologist Dr S Thanikachalam of Sri Ramachandra University. "This will help detect the disorder early and prevent damage," he says.

Hence, many doctors across specialties are demanding guidelines that would make 24–hour screening of patients with high–risk mandatory. The risk scale should include factors like family history of hypertension, obesity, smoking, alcohol, cholesterol levels, ECG and urine analysis.

In the last two years, Dr Rajan screened 247 healthy people who volunteered to donate one of their kidneys to relatives who required transplant. "We screened them at the clinic and then tied a small equipment on their wrist for a 24–hour screening. If the blood pressure is above normal (120/80) for more than 25% of the time, we consider them hypertensive. We found that nearly 13% of men and 9% women were hypertensive," he said. After two years, more than 50% of those with ‘masked’ hypertension developed sustained hypertension.

Transplant surgeons are also campaigning for a mandatory test for all donors who volunteer for live–donor organ transplant programme. "It is going to cost an additional 1,000. But this will prevent other complications in donors’ lives," says Dr Rajan Ravichandran.

Teenagers also prone to high BP
Chennai: Hypertension is no more just an adult disorder. City doctors say an increasing number of teens now suffer from hypertension along with high cholesterol levels and obesity.

A Chennai–based epidemiological study done by the MV Hospital on diabetes shows at least 5% of the children have high blood pressure and diabetes, says diabetologist Dr Vijay Vishwanath. "We have been seeing more and more children with such disorders in their teens, or even earlier. Such children normally have a faster heart rate and high obesity levels. Though many may require just lifestyle modifications, some are put on blood thinners very early in life," he said. Studies in cities like Delhi have also shown that 6% of children and teenagers suffer from hypertension.

"Many children today show signs of hypertension early in life even if they don’t have hypertension. To make things worse, they rarely exercise and their salt intake is high," said diabetologist Dr V Mohan, Madras Diabetes Research Foundation Hypertension among adolescents, pediatricians say, is often under–diagnosed. "We normally do not screen for hypertension in kids. It is mostly secondary to some diseases of the heart or kidney. But we are beginning to see high levels of cholesterol, obesity, hypertension and diabetes in teens. We have now consciously started checking for blood pressure in teens," says Dr Deepa Hariharan, pediatrician, Sooriya Hospital.

High blood pressure, they say, is also related to family history, fat and salt intake, low fruit and vegetable intake, and lower physical activity. "High hipwaist circumference, obesity and a family history of blood pressure are often indicators of hypertension among children. Considering its association with obesity, it should be investigated in pediatric clinics," said Dr Vijay.

Early Detection Is Key To Prevention
Normal blood pressure is 120/80
High Blood Pressure: If the doctor records blood pressure higher than 140/90, they consider the patient hypertensive

Masked Hypertension: This is a clinical condition in which a patient's BP level in the doctor’s clinic is normal, but otherwise, is at increased levels

White Coat Hypertension: This is a phenomenon in which a patient exhibits increased blood pressure only in a doctor's clinic. During other times, the pressure remains normal. It is believed that anxiety upon seeing the doctor leads to this experience

Golden Diagnosis Standard: If a patient has risk factors such as family history, doctors recommend 24–hour monitoring of BP. Those who show elevated BP more than 25% of the time are considered hypertensive. Doctors say that even if the blood pressure returns to normal, there is a need to reduce salt intake in the diet.

Ideal Salt Content: "Daily intake of more than 5g of salt results in a 23% chance of stroke and 17% risk of cardiovascular disease," says cardiologist Dr G Sengottuvelu of Apollo Hospitals. The average intake in the country is at least 9g, as against the WHO recommendation of 5g

High Salt Comes From:
Processed food is a dominant source of salt. Homemade preserved food such as pickles and papads also have high salt content

What Must Be Done: Doctors say that many countries like the UK, Japan and Finland have already made it mandatory to cut down on salt consumption. In the past 30 years, Finland has seen a 75% reduction in cardiovascular diseases in those under 65 years. Occurrence of stroke has dropped by more than 70% in Japan. It’s time lawmakers in India made a serious decision to prescribe standards for salt content

Never Too Young
High blood pressure is a disorder that is no longer confined to adults

• Studies have shown that hypertension or high blood pressure is more prevalent in Indian adolescents than in American kids
• Many children suffering from hypertension have a faster heart rate and high obesity levels
• Hypertension among children and teenagers is often unrecognised because nobody checks their blood pressure during medical examination
• Lifestyle management will help in reducing high BP and other cardiovascular risk factors often seen in Indian children