Early indicators of deteriorating renal efficiency in elderly subjects.

Renal functions decline with age. Only after considerable renal reserves are lost, the traditional clinical tests of urine, blood or clearance levels reveal the defect. The urine quantity & contents passed in 24 hrs both by young and elderly, show little differences between the two groups. Their creatinine clearances are also comparable. Earlier Studies on water dilution test had shown significant differences between the performance of the young and elderly subjects, indicating decrease in renal efficiency on ageing. In the present study 4 hourly collections of urine showed that the night collections in elderly subjects were comparatively larger in volume, electrolytes and other components as compared with younger subjects. The kidneys of the elderly seem to compensate by labouring at night, while the young have their restful phase. Thus in addition to water dilution test, comparison of day/night outputs of urine can be taken as an early indicator of renal deterioration in elderly.

Pulmonary functions of the elderly Indian subjects: trends of decline with age.

Respiratory Functions mainly vital capacity, FEV1, MBC and breath holding time, of 400 healthy elderly persons, 328 men and 72 women, aged 60+, sedentary and belonging to upper middle class from Bombay were studied. The findings are examined in each sex in 5 yearly age groups and are obviously low. An attempt is made to link the age-wise averages of VC in younger subjects in India reported by other workers with our data on elderly. The values from Northern groups are comparatively much higher than those from the rest of India. The connecting link in graphs shows a sudden fall when the data of northern Indians and that of our elderly are joined, but it is smooth when those of rest of India are connected.

Indican, ethereal and other forms of S eliminated in 24 hours urine by elderly Indian subjects.

Average daily excretion of Indican in urine of 42 healthy elderly men, av. age 69.9 +/- 5.0 years, (60 observations) was 60.7 +/- 17.4 mg/24 hrs. This is slightly higher than reported values for younger subjects. Average ethereal S elimination by Indian subjects has varied from 72-150 mg/day. Indican is the chief ethereal S eliminated in urine. Other forms of S excreted by elderly subjects were: Inorganic S 720 +/- 150 mg; Ethereal S 74 +/- 22 mg. Indican in them was 53.8 +/- 17.4 mg. This shows that the remaining 20 mg or about 1/4 of the ethereal S is eliminated in urine in other forms. Relationship with age, diet, common disorders along with findings in literature etc. are discussed.

Effects of age on renal efficiency.

Renal efficiency of 70 healthy subjects, 20 young av. age 27.2 +/- 5.8 yrs and 60 elderly av. age 68.2 +/- 4.7 yrs was studied by simple water elimination test in the monitoring under standard conditions. After drinking 2 litre of water, hourly samples of urine upto 4 hrs were collected for volume, sp. gr. urea, creatinine etc. The younger group passed 77% of the extra water drunk in 2 hrs and 92.5% in 4 hrs, whereas the elderly could throw out only 33% in 2 hrs and 56% in 4 hrs. The elderly showed much delayed and poorer elimination. The sp. gr., urea and creatinine in each sample of urine were less in the old indicating their inefficient elimination ability. Av. blood urea was 20.2 +/- 3.8 mg+ in young and 25.4 +/- 7.0 mg% in elderly, respectively. Calculated av. urea clearance value was 61.3 ml/mt in the young, while it was 39.4 ml/mt in the elderly. How well this simple test reflects the decreasing renal efficiency on ageing and compares with more elaborate tests like urea clearance is discussed.

Nitrogen and sulphur elimination in 24 hours urine by elderly Indians.

Urinary output of N2-urea, creatinine, uric acid, ammonia and organic and inorganic SO3 were repeatedly examined in healthy vegetarian subjects in Bombay--35 elderly and 2 young. Their routine diet examined for a week indicated an average intake of 56 g proteins (15 g animal) and excretion of about 8 g N2, 0.75 g of SO3 both in young and old subjects. These are much lower than figures reported for Europeans taking protein rich diets. Two elderly subjects supplemented their protein intake to 95 g/day (50 g animal) for 3 weeks. A progressive rise in the outputs of N2 and SO3 with increasing protein intakes was seen. SO3 estimation like that of N2 (urea) is indicative of the protein consumption of a person, but the estimations of urea output per day being easier are to be preferred.

Urinary nitrogen in elderly Indians.

Urinary volumes, nitrogenous consituents eliminated in 24 hrs urine and diet taken by healthy elderly lactovegetarian Indian subjects in Bombay are reported. The average values where: diet = 1603 calories, 52.3 gms proteins intake per day; urinary volume 1568 cc, urea 11.27 +/- 3.59 gms/24 hrs, creatinine 1.09 +/- 0.8 gms, uric acid 0.56 +/- 0.21 gms and ammonia 0.38 +/- 0.25 gms per day. While the values of all N2 constituents-urea, creatinine, uric acid and ammonia are much lower, the total N2 as well as urea output in elderly Indians in less than half of that of the young Europeans on meat rich diet but greater than those on protein free diets.