INTRODUCTION

Disease becomes more common with increasing age. Changes in connective tissue associated with the ageing process hastens degeneration of the vasculature leading to increasing cardio- and cerebro-vascular disease with age. As the internal organs function less efficiently with age, alterations in hormone levels and changes in the immune system lead to an increase in endocrine disorders, bone fragility and infectious disease in later life. Most cancers also are commoner in the elderly. The reason for this is not clear, but as life expectancy increases so does the incidence of cancer. Moreover, modern therapeutics allows many conditions to be treated well into the seventh and eighth decade to the extent that it is now often difficult to know what primary cause of death to put on the certificate of a recently decreased octogenarian.

At the BUPA Medical Centre we have been carrying out routine health screening for the last ten years. This paper presents data on biochemical constituents of blood and the changes that are seen in different age groups.

HEALTH SCREENING

The object of health screening is to detect disease at a ‘sub-clinical’ or a ‘pre-symptomatic’ phase in the belief that it will be more amenable to treatment at an early stage rather than at a late one (Beric Wright & Bailey, 1982). However, the majority of subjects attending a screening centre do not have overt disease and their characteristics can be used to study the relationship of age, among other factors, to the levels of various physiological and biochemical measurements. Four patterns of biochemical change associated with age are presented.