b. Experiments in Obese Subjects

Case 6. - J. L., young girl of eighteen years, parents obese, has been very fat since her thirteenth year; large, robust frame; height 1.685 m.; weight 98 kg.

The patient, who was perfectly healthy, happened to be staying in the hospital with her mother, who was suffering from diabetes. No notes in regard to the quantity of her urine or the specific gravity of her blood were made. The patient suffered greatly from thirst. The main-period of thirsting followed a foreperiod lasting from July 29 to August 3, and extended from August 4 to August 12. The amount of fluid-intake was at once reduced to 300 c. c. a day, and kept there. An after-period could unfortunately not be carried through. During the fore-period the average value for the oxygen consumption was 262.5 a minute, during the main-period 249.5 a minute. The figures obtained on August 7 and 8 are strikingly low. In this case, it may well be that the better control of voluntary muscle-movements, that the patient acquired as she became accustomed to the technique of the experiment, contributed somewhat to the progressive decrease in the values for the oxygen-consumption. However, it is certain that thirsting did not produce any increase of the oxygen-consumption.

The following table represents a summary of the figures obtained:

Case 7. - R. J., young girl of sixteen from a neuropathic family, no member of which was corpulent. Patient very fat since early childhood, and became relatively still more obese at thirteen and one-half years, after the onset of menstruation. It is stated that she never ate excessively, but, on the contrary, that she was, if anything, very moderate in her eating; it was also stated by the girl and her parents that she had plenty of exercise by taking long walks and helping with domestic duties. During the last few years she suffered from a variety of nervous disorders, i.e., vertigo, headache, insomnia. In addition a tendency to furunculosis was reported. Aside from her obesity the patient showed nothing abnormal; all the internal organs were sound; occasionally, however, the lips appeared slightly cyanotic. She was 1.63 m. tall, and weighed 72 kg.

In the course of this observation it was found that the patient represented a case of genuine constitutional obesity. The patient therefore received the following diet from March 18 to 26:

This diet contains about 1300 calories (equal about 18 cal. pro kilo.). The patient, who was carefully watched, increased her weight during nine days of this diet, from 71.4 to 71.9 kg. She was out of bed during the daytime and exercised considerably by taking walks through the garden. During a second period of observation her weight remained constant on a six-days' diet consisting of 2. 1/2 liters of milk and 200 g. of Graham bread (1900 calories = 26 calories pro kilo.).

After these preliminary facts had been determined, exact metabolic studies were undertaken with this patient. Whereas in all the preceding cases the diet was uniform but not regulated in every detail, with the exception of the amount of liquid allowed, the diet in this case was mathematically prescribed in order that some information in regard to her nitrogen-metabolism might be obtained.

The patient, during the fore-period that extended from December 19 to 29, received the following diet:

One liter of milk, 500 g. of coffee (extract made from 40 g. of coffee), 400 g. of bouillon, 100 g. of meat, 150 g. of bread, 1 egg, 80 g. of butter, 30 g. of sugar, 200 g. apple sauce, and 6 g. of nutrose (this food contained about 1900 calories and about 14 g. of nitrogen). The nutrose was given in order to bring the N of the food up to a certain value corresponding to that demanded by a previous determination of the N-metabolism in this case.

On this diet the patient maintained her weight, but retained considerable nitrogen.

During the main-period, that lasted from December 29, 1901, to January 7, 1902, bouillon and coffee were at first omitted from the diet, i.e., about 900 c. c. of fluid; from January 2 to 7 the 1 liter of milk, that now represented the whole fluid-intake, was reduced to 1/2 a liter. The nitrogen omitted by the withdrawal of the coffee and the bouillon was replaced by an equivalent quantity of meat-extract (6 g.), the nitrogen of the milk, that was withheld, replaced by an equivalent quantity of nutrose (19 g.), and the fat of the milk by butter (20 g.).

It was impossible to carry the restriction of liquids farther in this very sensitive patient. Even when we proceeded as above, she complained of very distressing thirst; at the same time the appetite was lost, so that the prescribed diet could only be eaten with reluctance.

The patient, however, lived up to her regime with great energy, because she was determined to do everything possible to reduce her fat. The table of Case 7 gives all the information in regard to the albumen and gas-metabolism of this patient.

This table shows that during the fore-period N was still retained, an average of 1.8 g. a day, while the weight of the patient remained essentially the same. The quantity of urine was abundant, but remained below the liquid-intake.

During the main-period the N-equilibrium was upset, in the sense that more N was excreted in the urine than was ingested; this did not render the Imbalance distinctly negative, but it indicated an increased destruction of body-albumen. The more pronounced and the more continued the restriction of liquids, the more did this become apparent; thus from January 4 on there was nitrogen-equilibrium, whereas prior to this date N was retained. The quantity of urine from this time on also rapidly decreased, the urine became more concentrated, and the output of water in the urine exceeded the intake of water by mouth.

This investigation, therefore, reveals the characteristic increase of albumen destruction during the period of thirsting. It is probable that an after-period with better flushing of the tissues would have shown a still greater increase of the urinary N-excretion; unfortunately this patient, whose appetite had become seriously impaired by the prolonged thirsting, could not in fairness be requested to undergo the further inconvenience of an after-period of observation.

We now come to the consumption of oxygen.

An increased oxygen-consumption could, at all events, not be determined. The average values for the period of thirsting and the after-period (the latter, for reasons outlined above, more important than the foreperiod) almost correspond, whereas a decrease of the average values, as compared to the fore-period, is noted.

It is important to emphasize that no appreciable loss of weight occurred during the period of thirsting. Unfortunately the insensible perspiration was not determined in this experiment, so that no exact analysis of this factor can be undertaken in this place.

Record Of The Consumption Of Oxygen