Quality of Life, Physical Activity, and Mental and Physical Health Status in Croatian Middle-Aged and Elderly Population

<b>Background/Objectives</b>: The proportion of middle-aged and elderly people in the total population is increasing, and it is of utmost importance to monitor their quality of life (QoL), which largely depends on mobility, health and mental state, diet, nutritional status (especially overweight and obesity). The population in Croatia is among the leading in terms of the proportion of overweight and obese people, therefore the aim is to study QoL and determine which aspects can potentially be mitigated by public health actions. <b>Methods</b>: In accordance with the available data from the SHARE study (Survey on Health, Aging and Retirement in Europe), data were taken from the most recently published-9th wave conducted in 2021/2022. In this study, the Croatian population older than 50 years is represented by 4687 respondents. Health-related parameters were monitored (cardiovascular diseases, diabetes, mental health, handgrip strength (HGS) as a biomarker in older people and body mass index) and quality of life (self-assessed quality of life (CASP, self-assessed health SPH, physical activity) and dietary habits. A logistic regression model was used to link HGS as a biomarker in older people with quality of life and health parameters. <b>Results</b>: There is an undeniable decline in social and physical activity with age; the proportion of people engaged in vigorous physical activity decreased from 47% in the 51-64 age group to only 5.4% in people over 85 years of age, while physical inactivity increased from 3% to 37.7%. Chronic diseases, especially hypertension, accumulate with age, while self-rated health worsens with age, as does mental health (the proportion of depressed people (according to the EURO-D scale) increased significantly from 21.1% in the 51-64 age group to 54.1% in those over 85 years of age). Results of multinomial logistic regression showed that sports (in)activity was consistently associated with a lower likelihood of reduced handgrip strength (OR = 1.94 for low strength, <i>p</i> < 0.001). <b>Conclusions</b>: Sports activities and social engagement are crucial for maintaining good handgrip strength. Higher BMI, lower education and adverse psychological states are risk factors for a weaker handgrip. These findings highlight the need for an integrated public health approach that promotes physical activity, balanced nutrition and mental and social well-being in the older population.