If there are other diseases present, this may have a very pronounced effect in increasing the risk of subsequent premature heart disease. The two most widely incriminated diseases are diabetes and high blood pressure (referred to as “hypertension” by doctors).
(i) Diabetes. Diabetes is a complex metabolic disease that basically involves the pancreas. Here certain cells fail to carry out their normal job, and this has an effect on insulin production and the storage of blood sugars.
In turn, this leads to an increased risk of atherosclerosis, the blood-vessel disease that predisposes to plaque and thrombus formation in the arteries, with the risk of heart attack.
For this reason, there is an increased likelihood of blood-vessel disease, particularly stroke and heart attack, in diabetics. The sex difference in the incidence of atherosclerosis and heart disease (with a male preponderance) does not occur among diabetics. (The words arteriosclerosis and atherosclerosis are used synonymously.) (ii) Increased Blood Pressure (hypertension). In recent years, the major importance of an increased blood pressure has been realised.
When the heart muscle contracts, blood surges out into the aorta to be distributed to the arterial system of the body. The pressure at this point is termed the systolic blood pressure. Between this instant and the next beat, a period of cardiac relaxation occurs. The pressure falls in the arteries momentarily, and this is referred to as the diastolic pressure. Therefore, the doctor always records two figures, the systolic followed by the diastolic.
The upper levels of normal are 140/90. (Pressures are recorded in millimetres of mercury on an instrument called a sphygmomanometer.) It is now well recognised that the lower diastolic pressure is the one of major importance. If this is perpetually raised, it means the heart is always working against a positive pressure. This increases its workload, and also this in some way increases the risk factors.
It seems that about 10 – 15 per cent of the total adult population in Western lands have a diastolic pressure of 110 mm or more. In some areas this proportion is more, in some places it is less. But it is a significant feature. Many heart specialists believe that there is an increased risk if the diastolic blood pressure is persistently above 95 mm. Of those adults in the 50- 59-years age group, as many as 40 per cent may then come into this category, which indicates the widespread nature of the risk factor.
The key point, of course, is to recognise if the blood pressure is elevated. If it is, then a reduction will prolong life and lessen the risk of premature heart attack.