A retrospective study has shown that the annual number of hospital in-patient discharges for urinary calculi in the U.K. increased by 45% between 1958 and 1969. The annual rate of discharges in the U.K. as a whole and in the various regions of the country was related to the real expenditure on food with a delay of 2 yr between the consumption of food and discharge from hospital for stones. The period of inflation between 1970 and 1976 caused a reduction in the expenditure on food. This coincided, 2 yr later, with a levelling off and, in some regions, a reduction in the number of discharges for calculi. Analysis of dietary composition over the period 1956-1976 revealed no relationship between the number of discharges for stones and the household consumption of calcium, oxalate, magnesium, phosphorus, refined carbohydrate or total protein. There was, however, a marked correspondence between the number of discharges for stones and the consumption of animal protein, particularly that derived from meat, fish and poultry. A fall in the consumption of dietary fibre and an increase in dietary acid may also have contributed to the observed changes in the pattern of stone-formation during the period of study. Mechanisms are suggested by which an increased intake of animal protein may increase the risk of stone-formation.
ASJC Scopus subject areas