Gout in the Filipino: Facts and Nuances
Associate Professor, UP College of Medicine
Gout remains a challenge in diagnosis and treatment. In the Philippines, it is estimated that 1.6 million Filipinos have the disease. It comprises about 30% of consultations in Arthritis Clinics. Hyperuricemia, the biochemical abnormality in gout, is present in about 28% of the general adult Filipino population. This abnormality is said to be associated with obesity and hypertension in both sexes, current smoking in men and menopause and abnormal creatinine in women. Hyperuricemia is postulated to be due to renal underexcretion of urates and this phenomenon is demonstrated through inability of 14 Filipino men to increase renal excretion of urates in response to a purine load.
Hospital-based reviews conducted in Metro Manila and Cebu depict that gout is predominantly (90%) found among males with age of onset at middle 50s to 60s and monoarticular in 70%. Among women, the onset of gout is seen at a later age and associated with depressed renal function on consult. Nephrolithiasis is found in a quarter, tophi are visible in a third, and renal insufficiency is evident in up to half of the population reviewed. The mean serum uric acid is 8-9 mg% and mean serum creatinine is 1.7 mg%.
The most common co-morbid conditions are hypertension and diabetes mellitus. In a cross-sectional study of 63 patients with gout in a tertiary training government hospital in 2012, the prevalence of metabolic syndrome is 47.6% and its most common component was abdominal obesity found in 39.7%.
There is young-onset gout (onset at < 30 years) in 15% of 669 patients seen in four adult rheumatology clinics in Metro Manila and South Luzon. There is family history of gout in 47% of these patients. The characteristics and disease presentation of these young individuals, all men, mirror those of adults. There is an interval of approximately 10 years between onset and consult with a rheumatologist. On presentation at the clinic, 34% have polyarticular disease and 37% have estimated creatinine clearance < 60 ml/min. These apparent signs of complicated disease are potentially preventable with appropriate treatment.
There are many inconsistencies between knowledge of Filipino physicians about the management of gout and the recommendations in clinical practice guidelines. Two surveys in a tertiary training government hospital done in 1999 and in 2014 show that there is use of urate-lowering drug for asymptomatic hyperuricemia in 20-30%. There are no studies on outcomes of treatment for gout and patient knowledge and perceptions about the disease. These are important areas to study in addition to a revisit of prevalence of disease and identification of genetic/molecular defects responsible for hyperuricemia in our population. It is time for greater efforts to control this disabling and potentially fatal disease.