High blood pressure is a major health problem in Bermuda. In 2006 more than a quarter of the adult population said they had the condition and it is believed the percentage has likely grown since then.In fact Government is so concerned that a set of guidelines was compiled and given to local healthcare professionals in September giving a standard of care to which those with the condition are now treated. In this way Government, through the Department of Health, can now say it is managing the condition.And managing it is important because high blood pressure (hypertension) is a leading cause of type-2 diabetes, strokes and the Island’s number one killer heart attacks. It also leads to complications like renal failure which result in costly dialysis treatment.Body & Soul, in support of the Department of Health’s hypertension awareness campaign, spoke with Dr Lynnette Thomas, Director of Dialysis at King Edward VII Memorial Hospital. Dr Thomas explained the impact of high blood pressure on the kidneys.November is Diabetes Awareness month, and it should be noted that diabetics are at increased risk of renal failure if their blood pressure is not well managed.Question: From your point of view, how severe a problem is hypertension in Bermuda?Answer: Hypertension is a major public health concern in Bermuda. We know that hypertension is a major risk factor for cardiovascular disease, stroke and kidney disease. We also know that cardiovascular disease is the leading cause of death among Bermudians. It is presumed that efforts to reduce both the incidence of new hypertension diagnoses and also efforts to improve treatment of hypertension to goal, as it exists, would be expected to translate into a reduction in deaths and disability attributable to heart disease and its complications.Q: You work in the Dialysis Unit. Is hypertension the cause for most of those having dialysis?A: What we have found is that approximately 40 percent of our dialysis population carry a diagnosis of hypertension. A proportion of those patients will have hypertension as the CAUSE for their end stage renal disease, and another proportion may have renal disease attributable to another cause, with resultant hypertension. It is very difficult to know which category patients fall, but it can extrapolated from some studies that approximately 50-60 percent of those patients have hypertension as the major cause of their end stage renal disease.Q: What percentage of dialysis patients does this represent?A: Of our 120 dialysis patients, approximately 48 have hypertension. Of that 48, approximately 24 have end stage renal disease purely related to ongoing, poorly controlled hypertension. This suggests that approximately 20 percent of our patients with end stage renal disease will have hypertension as the cause.Q: How many people are having dialysis at KEMH (on average) a year?A: Our current census is 120 patients, undergoing chronic haemodialysis treatments. This number is increasing yearly.Q: How exactly does hypertension lead to dialysis?A: Longstanding and poorly controlled hypertension leads to damage in multiple organs, and the mechanism is similar. Prolonged high blood pressure within our delicate blood vessels leads to microscopic vessel damage. This damage accumulates over time. The end result is damaged blood vessels unable to deliver enough blood to the brain, heart and kidneys. This places persons with high blood pressure at significant risk for coronary disease including heart attack, stroke and loss of kidney function.The kidneys are ten to 12-centimetre organs on either side of our spine, which are composed primarily of delicate blood vessels. Our entire blood volume is circulated through our kidneys about 30 to 50 times per day for removal of fluid and toxins. When blood pressure remains elevated, there is ongoing microscopic damage occurring in the kidney vessels. As with all damage to tissues in our body, we heal with scar.When the kidney has replaced enough viable kidney tissue with scar from damage caused by high blood pressure, kidney function begins to decline. We can actually watch, with ultrasound imaging, the kidneys begin to shrink over time (years) from scarring. This form of kidney disease tends to be slowly progressive if blood pressure is not controlled, and without a kidney transplant, the person may eventually require haemodialysis.There is also a form of hypertension which is caused by damage to the kidney. Persons with previously normal blood pressure may develop hypertension in the setting of an acute or chronic renal disease. Although the hypertension is not the cause for renal disease in this population, we know that continued uncontrolled hypertension can significantly hasten progression to renal failure requiring haemodialysis. For example, persons with renal disease associated with their diabetes, will have faster progression to end stage renal disease, if blood pressure is not aggressively lowered.Therefore, there are forms of renal disease caused by long-standing hypertension which can progress to renal failure, as well as forms of renal disease not caused by hypertension, but which will worsen more rapidly if hypertension is uncontrolled.Q: In your view is hypertension preventable for most people?A: While we know that there are genetic factors related to the risk of developing hypertension in fact, being of the black race is a major risk factor the other major risk factors for hypertension in our population are related to modifiable factors such as excessive salt intake, excessive alcohol intake, obesity, physical inactivity and elevated cholesterol levels. These factors certainly suggest that through lifestyle modification, hypertension can be avoided or at least amelioratedQ: We know that salt and lack of exercise are two major contributing factors for hypertension, in your view and how significant is worrying in increasing blood pressure?A: We certainly know through various studies that worry, anxiety and emotional stress cause release of hormones which can temporarily raise blood pressure. We have also been able to demonstrate through biofeedback, our ability to calm ourselves and thus lower blood pressure. It has been my professional experience though, that patients who present with severely high blood pressure readings on more than one occasion, fit the definition of hypertension and should be treated even if stress is a factor.Q: Is there anything that you would like to see GPs doing more of to cut down on the problem of high blood pressure?A: There have been studies which suggest that we are not aggressive enough with blood pressure lowering. Patients with known hypertension are walking around with blood pressures above goal ([ one of which should be a diuretic. I also recommend frequent blood pressure checks with up-titration of medications, until goal blood pressure is attained. Patients MUST take responsibility for their own health by being compliant with their medications and salt intake and following their physicians’ advice.Careful monitoring of kidney function in hypertensive patients is essential. Current guidelines recommend measurement of creatinine and glomerular filtration rate both of which are approximate measures of kidney function at initial evaluation of a patient with hypertension and at least yearly. A urine dip stick and measurement of urinary protein should also be performed yearly. Negative changes in a patient’s renal function should be promptly evaluated.In regards to screening for hypertension, the 2007 United States Preventive Services Task Force (USPSTF) guidelines on screening for high blood pressure recommend screening every two years for persons with systolic and diastolic pressures below 120 mmHg and 80 mmHg, respectively (normal BP in JNC 7), and yearly for persons with a systolic pressure of 120 to 139 mmHg or a diastolic pressure of 80 to 89 mmHg.