An update on 'progression promoters' in renal diseases.

AIM: This paper reviews progression in renal diseases.
METHODS: An English language literature search using Medline (1980 January-2001 July) was done to assess research and review articles on progression in renal diseases.
RESULTS: Factors that increase the risk of progression in renal diseases are hypertension, dyslipidaemia, underlying nephropathy, high dietary protein intake and proteinuria. Others are smoking, hyperglycemia, low birth weight, obesity, metabolic syndrome X, genetic factors such as angiotensin converting enzyme 'DD' genotype and chromosome 1q21, and exposure to lead. Hypertension induces arteriolar nephrosclerosis. The mechanisms whereby lipids contribute to vascular and renal injury are incompletely understood. Glomerular hyperperfusion and increased proteinuria may explain the adverse effects of increased protein intake on renal disease progression. Proteinuria contains numerous toxic/inflammatory systems that promote progression. Cigarette smoking has vasoconstrictive, thrombotic and direct toxic effects on the vascular epithelium. Hyperglycemia is strongly implicated in the progression of complications in diabetics. Oligonephropathy in low birth weight has been suggested to increase the risk for systemic and glomerular hypertension in adult life. In obesity, the combination of hyperfiltration, glomerular hypertrophy and glomerular hypertension is a primary initiating event for glomerular injury manifesting as glomerulomegally and focal and segmental glomerulosclerosis and proteinuria. Angiotensin I, with enzyme insertion/deletion polymorphism, especially the "DD" genotype, predisposes to a rapid decline in renal function. Finally, long-term exposure to low levels of environmental lead affects renal function.
CONCLUSION: The control of hypertension, dyslipidaemia, proteinuria, obesity, avoidance of low birth weight, smoking and heavy metals such as lead are intervention strategies for preventing progression of renal diseases.