I medici sono in genere più preoccupati dell’aumento ponderale che delle perdite di peso dei loro pazienti in età avanzata; sarebbe invece il calo ponderale ad associarsi a una prognosi meno favorevole, e specificamente a un aumento del rischio di mortalità per tutte le cause e per le principali patologie (tumori, malattie cardiovascolari). Lo suggerisce questo recente articolo, relativo alla coorte dello studio ASPREE (Aspirin in Reducing Events in the Elderly), costituita da circa 16.500 soggetti di età media di 75 nell’arruolamento, seguiti per una media di 4,4 anni.
Gli autori hanno osservato che il rilievo di un calo ponderale anche limitato (tra il 5% e il 10%) durante il periodo di osservazione si associava ad un aumento della mortalità totale del 33% tra gli uomini e del 26% tra le donne, rispetto ai soggetti senza modificazioni del peso. Cali superiori al 10% si associavano ad aumenti molto più pronunciati (da due a tre volte) della mortalità stessa. La riduzione della circonferenza addominale aveva effetti meno sfavorevoli, mentre l’aumento ponderale si rivelava sostanzialmente irrilevante.
L’associazione tra mortalità e calo ponderale si manteneva significativa anche eliminando dalle valutazioni del rischio i soggetti deceduti nei primi due anni del periodo di osservazione, durante i quali il calo ponderale poteva segnalare malattie croniche in fase di sviluppo.
L’aumento della mortalità associato al calo del peso era maggiore tra i soggetti di sesso maschile: un’osservazione che potrebbe riflettere il diverso contributo del tessuto adiposo al peso complessivo, maggiore tra le donne. Negli uomini, quindi, il calo ponderale indicherebbe più spesso un calo della massa muscolare o ossea, prognosticamente meno favorevoli.
Il formato dello studio non consente, come è noto, di definire relazioni causa-effetto, e quindi di stabilire con certezza se fosse il calo ponderale ad essere responsabile dell’aumento di mortalità osservato; tuttavia, i risultati raccolti suggeriscono che, in età avanzata, il medico dovrebbe valutare con attenzione ogni reazione del peso dei suoi pazienti.
Associations of Change in Body Size With All-Cause and Cause-Specific Mortality Among Healthy Older Adults
Hussain SM, Newman AB, Beilin LJ, Tonkin AM, Woods RL, Neumann JT et al.
JAMA Netw Open. 2023 Apr 3;6(4):e237482. doi: 10.1001/jamanetworkopen.2023.7482.IMPORTANCE: The association between weight change and subsequent cause-specific mortality among older adults is not well described. The significance of changes in waist circumference (WC) has also not been compared with weight change for this purpose.
OBJECTIVE: To examine the associations of changes in body weight and WC with all-cause and cause-specific mortality.
DESIGN, SETTING, AND PARTICIPANTS: This cohort study is a post hoc analysis of data from the Aspirin in Reducing Events in the Elderly (ASPREE) randomized clinical trial, which recruited participants between March 1, 2010, and December 31, 2014. The study included community-based older adults (16 703 Australian participants aged ≥70 years and 2411 US participants aged ≥65 years) without evident cardiovascular disease (CVD), dementia, physical disability, or life-limiting chronic illness. Data analysis was performed from April to September 2022.
EXPOSURES: Body weight and WC were measured at baseline and at annual visit 2. Analysis models were adjusted for baseline body mass index because height and weight were measured at baseline, allowing for calculation of body mass index and other variables. Both body weight and WC changes were categorized as change within 5% (stable), decrease by 5% to 10%, decrease by more than 10%, increase by 5% to 10%, and increase by more than 10%.
MAIN OUTCOMES AND MEASURES: All-cause, cancer-specific, CVD-specific, and noncancer non-CVD-specific mortality. Mortality events were adjudicated by an expert review panel. Cox proportional hazards regression and competing risk analyses were used to calculate hazard ratios (HRs) and 95% CIs.
RESULTS: Among 16 523 participants (mean [SD] age, 75.0 [4.3] years; 9193 women [55.6%]), 1256 deaths were observed over a mean (SD) of 4.4 (1.7) years. Compared with men with stable weight, those with a 5% to 10% weight loss had a 33% higher (HR, 1.33; 95% CI, 1.07-1.66) risk of all-cause mortality, and those with more than a 10% decrease in body weight had a 289% higher (HR, 3.89; 95% CI, 2.93-5.18) risk. Compared with women with stable weight, those with a 5% to 10% weight loss had a 26% higher (HR, 1.26; 95% CI, 1.00-1.60) risk of all-cause mortality, and those with more than a 10% decrease in body weight had a 114% higher (HR, 2.14; 95% CI, 1.58-2.91) risk. Weight loss was associated with a higher cancer-specific mortality (>10% decrease among men: HR, 3.49; 95% CI, 2.26-5.40; 5%-10% decrease among women: HR, 1.44; 95% CI, 1.46-2.04; >10% decrease among women: HR, 2.78; 95% CI, 1.82-4.26), CVD-specific mortality (>10% decrease among men: HR, 3.14; 95% CI, 1.63-6.04; >10% decrease among women: HR, 1.92; 95% CI, 1.05-3.51), and noncancer non-CVD-specific mortality (>10% decrease among men: HR, 4.98; 95% CI, 3.14-7.91). A decrease in WC was also associated with mortality.
CONCLUSIONS AND RELEVANCE: This cohort study of healthy older adults suggests that weight loss was associated with an increase in all-cause and cause-specific mortality, including an increased risk of cancer, CVD, and other life-limiting conditions. Physicians should be aware of the significance of weight loss, especially among older men.