Higher uric acid is associated with higher rate of metabolic syndrome in Chinese elderly

Occurrence of metabolic syndrome components in northerners

The metabolic syndrome is currently becoming more common. It is a significant public health concern as it is epidemic affecting populations in many regions of the world. In Magadan region no research has been carried out to study the frequency of components of the metabolic syndrome among northerners. This survey was performed to assess the occurrence of the main and additional components of the metabolic syndrome among 17 to 74 year old residents of the Northern region. Two hundred and forty north born Caucasians participated in the study: male subjects at their young age, working age, and retirement age, all belonging to the territory of Magadan region. We used photometric, immunochemiluminescent research methods, as well as standard methods for assessing body mass index and cardiovascular system. The metabolic syndrome factors were determined in accordance with the criteria of the National Cholesterol Education Program (NCEP), the Adult Treatment Program III (ATP III), the International Diabetes Federation (IDF), and the Consensus of International Experts in Cardiology and Endocrinology. We analyzed five main components of the metabolic syndrome (overweight, carbohydrate metabolic impairments hypertension, hypertriglyceridemia, hypoalphacholesterolemia) and three additional components (presence of insulin resistance, purine metabolism disorder, deficient and insufficient concentrations of vitamin D). Combinations of the components were also studied through the examined age groups. According to the ATP III, NCEP and IDF criteria, the metabolic syndrome was more common in elderly subjects (47%) than in working age (21%) or young examinees (3%). Older males tended to exhibit higher frequency of both the main and additional factors of metabolic syndrome. The total index of the occurrence of metabolic syndrome factors in the group of young men was 101%; in the group of men of working age - 180%, and in men of retirement age - 274%. The results on occurrence of the metabolic syndrome components observed in the surveyed groups of northerners can make an information data base, which we assume can be applied when planning and carrying out scientifically grounded preventive measures, which will improve subjective quality of life and its expectancy under the North conditions.

The Power of Serum Uric Acid in Predicting Metabolic Syndrome Diminishes With Age in an Elderly Chinese Population

OBJECTIVES

Although serum uric acid (sUA) is not a criterion for diagnosing metabolic syndrome (MetS), many studies have identified a positive association between sUA and MetS in patients of various ages and ethnicities. This association has not been fully established in the very elderly.

DESIGN

Cross-sectional and longitudinal study.

SETTING AND PARTICIPANTS

A total of 18,906 Chinese elderly aged 65 and older undergoing routine health checkups in Taiwan were enrolled.

MEASUREMENTS

Modified Adult Treatment Panel III criteria were used to define MetS. All participants were further divided into nine groups with gender specification according to age (the young-old, 65 to 74; old-old, 75 to 84; and oldest-old, 85 and over) and sUA concentration tertile (males: sUAG1, <5.7 mg/dL; sUAG2, 5.7-6.7 mg/dL; and sUAG3, > 6.7 mg/dL; females: sUAG1, <4.9 mg/dL; sUAG2, 4.9-5.9 mg/dL; and sUAG3, > 5.9 mg/dL). A cross-sectional study was first performed to determine the correlation between sUA and MetS and its components. A longitudinal study then excluded subjects with MetS at baseline to explore the risk of MetS according to sUA levels in 3 age groups.

RESULTS

In the cross-sectional study, we observed a graded, positive association between sUA and MetS components that diminished after age 75. Subjects with higher sUA levels had higher odds ratios (OR) for the occurrence of MetS in the young-old and old-old groups of both sexes (P<0.001) except sUAG2 males in the old-old group. However, the association diminished with age and only a higher OR was observed in sUAG2 males in the oldest-old group (OR, 3.38; 95% CI, 1.11-10.30; P = 0.032). In the longitudinal study, the Kaplan-Meier plot showed that higher sUA levels were associated with a higher risk of MetS in the young-old group of both genders (P < 0.001 sUAG3 vs. sUAG1 and sUAG2). Cox regression analysis further confirmed these results (young-old group: sUAG3 HR, 1.90; 95% CI, 1.42-2.54; P < 0.001; old-old group males: HR, 2.20; 95% CI, 1.04-4.65; P = 0.039; young-old females: HR, 1.83; 95% CI, 1.38 - 2.43; P < 0.001).

CONCLUSIONS

Higher sUA levels in the young-old group of Chinese elderly were associated with a higher risk of developing MetS. sUA levels are thus regarded as a potential tool for early diagnosis of MetS. However, this association diminished in those over 75 years of age.