People would be more concerned in maintaining a normal body weight if they understood the dangers of over-weight. Usually they either ignore the excess, or are interested in reducing merely from the point of view of appearance. This indifferent attitude is maintained until some accident attributable to the overweight occurs. We believe that a frank statement of the dangers of this condition is the most convincing argument in favor of its prevention and adequate treatment.
Shortening of the Span of Life. Prominent life insurance companies have collected comprehensive statistical data which demonstrate the risk of obesity from an insurance point of view. These show that for each pound a person is overweight or underweight, excepting possibly only a very few pounds variation from the average, the expectancy of life is decreased by one per cent. For example, a woman forty years of age, and five feet five inches tall with shoes, should weigh about 134 pounds dressed. At this weight her life expectancy would be twenty-eight years, according to actuary tables. If, how-ever, at this age she actually weighs 184 poundsthat is, she is fifty pounds overweight, her life expectancy is reduced to fourteen years. Instead of expecting to live to be sixty-eight, she can expect to live to be only fifty-four years of age.
Enlargement of the Heart. It is believed that the heart must enlarge to carry on efficiently in the presence of excess body weight. We have made thousands of measurements of the plane surface of the heart shadow by means of the fluoroscope, and have found that the transverse diameter of the heart in relation to the internal trans-verse diameter of the chest, is increased in most over-weight patients, particularly in those in whom obesity is of long standing. This change in the transverse diameter may not be a measure of permanent cardiac enlargement, because we see it diminish frequently after body weight has returned to normal. The deposit of fat about the heart, a changed position of the heart due to deposits of fat in the abdomen, and actual increase in the mass of the heart muscle resulting from an increased load in circulation, may explain what is observed. Clinically, the function of the heart is increasingly impaired as the relative heart diameter exceeds 50 per cent, whatever may be the cause. It is believed that the placing of fatty tissue about and in the muscles of the heart, at times is accompanied by actual impairment of the function of the organ. Although the orthodiagram is the best simple method of estimating heart size, it does not give full information regarding the volume of the heart. This detail we hope may be made clear by further studies of this subject.
Increased Blood Pressure. Most of our series of obese patients have hypertension. Similar to the enlargement of the heart, this condition might be expected from mechanical considerations. Increased pressure would be necessary to carry blood through the extra network of blood vessels in the added body tissue. As the blood pressure rises, enlargement of the heart is necessary in order to perform the additional work required. There-fore, we see the largest hearts in obese patients with elevated blood pressure. In our own series of patients, blood pressure readings have fallen as body weight approached normal. To some degree this has been observed even when the hypertension was not obviously secondary to the obesity. Similar observations upon the association of overweight and hypertension have been made in other clinics.
Development of Arteriosclerosis. There is consider-able evidence that hypertension from any cause is associated with varying degrees of hardening of the arteries and arterioles. Also it is believed by some workers that certain products in the metabolism of fat may directly contribute to the hardening of vessel walls.
Relation to Diabetes Mellitus. Obesity is so commonly followed by or associated with diabetes that leading authorities consider it to be one of the most important factors in the onset of this serious disease. More than one-half of the adult patients in our own diabetic series have been overweight with enlargement of the heart and high blood pressure at the beginning of their treatment. Those whose family histories record the presence of diabetes should be on the watch to prevent the earliest tendency to weight increase.
Lowered Body Resistance. It is said that general body resistance is usually lowered in the presence of obesity, so that obese individuals are more susceptible to such common diseases as pneumonia and influenza. The prognosis is more grave in the obese than in normal persons.
Greater Surgical Risks. In the presence of obesity the risks of surgery are increased. The response of the patient to certain anesthetics and of the fatty tissues to handling during surgery is less favorable than in persons of aver-age weight. Infection in body fat is not easily cleared up. Certain operations are more common in overweight people; for example, those for gall bladder irritation, gall stones, etc. Surgeons frequently approach such surgery with a degree of reluctance because of the frequency with which post-operative complications appear. Often only an emergency need will justify surgery.
Increased Tendency to Skeletal Strains and Injuries. Injury involving skeletal structures such as bones and ligaments are seen more frequently in persons of excess weight. Strains of the back (sacro-iliac) or foot strains, flat feet, weak arches, and non-infectious joint changes may be thought of as mechanical complications, where a greater load is imposed on structures than they are fitted to carry.