HAPA-based Intervention in Adults With Metabolic Syndrome and Chronic Kidney Disease

Metabolic syndrome (MetS) is a worldwide chronic disease mainly due to unhealthy diets and sedentary lifestyles. According to the International Diabetes Federation (IDF) definition of MetS, patients must have central obesity defined by waist circumference (WC) with ethnicity-specific values, plus any two of four additional factors, namely high triglycerides (TG), low high-density lipoprotein cholesterol (HDL-C), high fasting glucose (FG), and high blood pressure (BP). More recent evidence indicates that the MetS could be an independent risk factor for chronic kidney disease (CKD). CKD is a progressive and incurable condition with high morbidity and mortality, defined by markers of kidney damage or decreased glomerular filtration rate (GFR) persisting for at least three months. According to KDIGO 2012 clinical practice guideline, CKD is divided into five stages (stages 1, 2, 3a, 3b, 4, 5), which are based on the eGFR test result, as the stage progresses, kidney function becomes more severe, ultimately leading to kidney failure. Previous studies have found that individuals with MetS had a higher risk of CKD compared with patients without MetS. Central obesity, as the core component of MetS, could be one of the most essential pathogenes explaining the association between MetS and CKD. Central obesity mainly manifests as excess abdominal adipose tissue, which directly leads to the deranged synthesis of various adipose tissue cytokines (e.g., leptin, adiponectin, resistin, and visfatin) with nephrotoxic potential to cause sustained damage or structural changes to the kidneys, as well as indirectly trigger insulin resistance, dyslipidemia and hypertension, which are the most substantial risk factors for CKD. Many patients fail to take MetS seriously until they are diagnosed with CKD. This is attributed to the additional complications and complex treatments associated with CKD, significantly affecting their daily lives. Current therapeutic guidelines for MetS suggest that non-pharmacological interventions with multifactorial lifestyle changes should be the primary treatment, including dietary modification, physical activity (PA), counselling or lifestyle modifications. The Health Action Process Approach (HAPA) offers such a framework by distinguishing processes (risk perception, outcome expectancies and action self-efficacy) from volitional processes (action planning, coping planning, and maintenance and recovery self-efficacy). Application of HAPA is therefore well suited to supporting behavior change under the unique constraints of coexisiting MetS and CKD. Despite high prevalence and synergistic risks of this dual diagnosis, behavioural intervention research has largely overlooked the population. Existing non-pharmacological programmes typically target MetS or CKD in isolation and do not systematically reconcile their conflicting dietary and lifestyle requirements. This study therefore evaluates the effectiveness of a HAPA-based behaviour change intervention on WC and kidney function in Chinese adults with both MetS and CKD.