Cognitive function, body weight and body composition ... - Springer Link

Z Gerontol Geriat 40:13–20 (2007) DOI 10.1007/s00391-007-0428-4

CONTRIBUTION TO THE MAIN TOPIC

R. Wirth J. M. Bauer C. C. Sieber

Cognitive function, body weight and body composition in geriatric patients

Kognitive Funktion, Körpergewicht und Körperzusammensetzung bei geriatrischen Patienten " Abstract Weight loss is a frequent concomitant observation in dementia syndromes and is known to worsen the prognosis of elderly patients. This is a retrospective cross-sectional study of 1575 consecutive geriatric patients to obtain data about body weight and body composition in relation to gender and cognitive

Received: 6 December 2006 Accepted: 18 December 2006

Dr. med. Rainer Wirth ()) Klinik für Akutgeriatrie St.-Marien-Hospital Borken GmbH 46322 Borken, Germany E-Mail: [email protected] J. M. Bauer · C. C. Sieber Medizinische Klinik 2 – Geriatrie, Klinikum Nürnberg Lehrstuhl für Innere Medizin – Geriatrie Universität Erlangen-Nürnberg

function. Fat mass (FM) and fatfree mass (FFM) were determined by bioelectric impedance analysis. Subjects with severe cognitive dysfunction (MMSE < 11) had a significant lower body weight (6.5%), BMI (5.7%), FM (15.7%) and fat mass index (14.3%) than subjects without cognitive dysfunction (MMSE > 26). FFM was not significantly decreased (2.1%). Subgroup analysis showed that mean body weight is closely related to the degree of cognitive dysfunction. Gender-related analysis showed no significant difference in body weight, BMI, FM and fat-mass index (FMI) between male subjects with severe cognitive dysfunction and male subjects with normal cognitive function. Only FFM was significantly decreased (7.0%) in males with severe cognitive dysfunction. Findings of this study indicate that patients with cognitive dysfunction lose substantial amounts of body weight, related to the degree of cognitive dysfunction. In this connection, female subjects seem to lose more weight than male subjects. At the same time female subjects predominantly lose FM, whereas male subjects seem to lose mainly FFM. Therefore patients with cognitive dysfunction should be regularly screened for weight loss and malnutrition to enable early nutri-

tional intervention to prevent relevant weight loss. Future studies on weight loss in dementia should consider gender-related differences in body composition and weight loss. " Key words bioelectric impedance analysis – BIA – BMI – body composition – body weight – cognitive function – dementia – fat mass – fat-free mass – geriatric patients – malnutrition – weight loss " Zusammenfassung Gewichtsverlust verschlechtert die Prognose älterer Patienten und ist eine häufige Begleiterscheinung dementieller Syndrome. Die vorliegende Studie ist eine retrospektive Querschnittsuntersuchung an 1575 konsekutiven geriatrischen Patienten, die Daten zu Körpergewicht und Körperzusammensetzung in Beziehung zu Geschlecht und kognitiver Funktion analysiert. Die Fettmasse (FM) und fettfreie Masse (FFM) wurde mittels bioelektrischer Impedanzanalyse bestimmt. Patienten mit schwerer kognitiver Störung (MMSE < 11) hatten ein signifikant niedrigeres Körpergewicht (6,5%), einen niedrigeren BMI (5,7%), eine niedrigere FM (15,7%) und einen niedrigeren Fettmassen-Index (14,3%) als Patienten ohne kognitive Störung

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(MMSE > 26). Die FFM war nicht signifikant erniedrigt (2,1%). Die Subgruppenanalyse zeigt, dass das mittlere Körpergewicht in enger Beziehung zur Ausprägung der kognitiven Störung steht. Die geschlechtsspezifische Auswertung zeigt keine signifikanten Unterschiede bei Körpergewicht, BMI, FM und Fettmassen-Index zwischen männlichen Patienten mit schwerer kognitiver Störung und jenen mit normaler kognitiver Funktion. Nur die FFM war bei männlichen Patienten mit schwerer kognitiver Störung signifikant erniedrigt (7,0%).

Die Ergebnisse dieser Studie zeigen, dass Patienten mit kognitiver Störung in Abhängigkeit vom Grad der kognitiven Störung in relevantem Ausmaß Körpergewicht verlieren. Frauen scheinen hierbei mehr Körpergewicht zu verlieren als Männer. Gleichzeitig verlieren Frauen vorwiegend FM, während Männer überwiegend FFM verlieren. Aus diesem Grund sollten Patienten mit kognitiver Störung regelmäßig auf Gewichtsverlust und Malnutrition untersucht werden, um mit Hilfe einer frühzeitigen Ernährungstherapie einen relevanten Gewichtsverlust

Introduction Several studies show that obesity is a strong risk factor for developing dementia in later life [1–3]. From that point of view, we would expect patients with dementia to have a higher body mass index (BMI) and body weight than non-demented subjects. Nevertheless, in cross-sectional studies comparing non-demented with demented patients, a lower BMI and body weight in the dementia group can be regularly observed [4–9]. This observation can only be explained by substantial weight loss during the ongoing disease, which has been documented by numerous studies [5, 10–19]. Since the early description of dementia it is well known that most of the patients suffering from dementia show serious weight loss, sometimes already at an early stage of the disease and regularly during the forthgoing disease [5, 20]. Some longitudinal studies even show a significant weight loss preceding the syndrome and its diagnosis in many subjects [21]. Weight loss and malnutrition in general is an underestimated problem in health care, which is frequent in geriatric patients [22–24]. Patients with malnutrition and weight loss have an increased rate of complications, longer hospital stays and a poor functional outcome, as well as an increased mortality [8, 25–32]. Data of clinical studies show that the poor outcome of patients with malnutrition can be partly reversed by nutritional intervention [33, 34]. Malnutrition in dementia is a special challenge, because mechanisms of weight loss in dementia remain unclear and effective therapeutic strategies are not yet validated and seem difficult. What so far has not been well analyzed is the question whether patients with dementia and cogni-

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zu vermeiden. Zukünftige Studien über Gewichtsverlust bei Demenz sollten die geschlechtsspezifischen Unterschiede bei Körperzusammensetzung und Gewichtsverlust berücksichtigen. " Schlüsselwörter Bioelektrische Impedanzanalyse – BIA – BMI – Demenz – Fettmasse – fettfreie Masse – Gewichtsverlust – kognitive Funktion – Körpergewicht – Körperzusammensetzung – geriatrische Patienten – Malnutrition

tive dysfunction predominantly lose fat mass (FM) or fat-free mass (FFM). A loss of fat-free mass, which mainly consists of muscle mass, could be caused by muscle atrophy due to functional decline and not by malnutrition per se. Furthermore, it is not clear whether there are differences in weight loss and body composition changes between male and female subjects. In fact, in one study, a substantial weight loss was only observed in female subjects with dementia [35]. It is also unclear whether there is a connection between body weight and weight loss and severity of cognitive dysfunction.

Objectives To determine body weight, body mass index (BMI) and body composition in relation to cognitive function in a geriatric population, including potential gender differences.

Methods n Patients This study is a retrospective, cross-sectional study of 1575 consecutive patients of an acute geriatric hospital unit. We analyzed the patients’ body weight, body height, BMI, age, sex, cognitive function and the data of bioelectric impedance analysis (BIA) concerning FM and FFM to obtain data about body composition in relation to cognitive function. To minimize a possible bias of nutritional treatment, only the first hospital admission of patients with repeated admissions was analyzed.


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n Methods

Results

All data were obtained within the first three days of the hospital stay. Body weight was measured in 94% of the patients. In 6% this was not possible due to the severity of disease. In these patients body weight was estimated. Body height was measured in 91% of the patients. Where this was not possible (9%), body height was calculated with knee height [36] or approximately measured in bed. Cognitive function was measured with the mini mental state examination (MMSE) in clinical routine [37]. When the MMSE could not be performed due to severe cognitive dysfunction, 0 points were given. Subjects who could not perform the MMSE due to dysphasia or motor impairment were excluded from the analysis. The bioelectric impedance was measured with the device BIA-2000-M of Data-Input-GmbH in a multifrequency, tetrapolar technique on the right side of the body. Red Dot 2271 (3M) electrodes were used. The time of measurement was not standardized. Fat mass (FM) and fat free mass (FFM) were calculated with the software NutriPlus (version 5.1) of Data-Input-GmbH. To put FM and FFM in relation to body stature, the fat mass index (FMI) and fat-free mass index (FFMI) were calculated analogous to BMI (FMI+FFMI= BMI) [38, 39]. Before the statistical analysis was performed, 18 patients had to be excluded because the BIA software calculated a negative fat mass, which is not plausible and which is a common problem in BIA, performed in patients with disturbances of hydration status [40–43]. Nevertheless BIA measurements are regarded as sufficient, when analyzing patient groups [44, 45].

n Characteristics of the entire study population

n Statistical analysis For the purpose of group analysis, subjects were divided into 4 different groups with severe cognitive dysfunction (MMSE < 11 pts), moderate cognitive dysfunction (MMSE 11–19 pts), mild cognitive dysfunction (MMSE 20–26 pts) and without cognitive dysfunction (MMSE > 26 pts). Statistical analysis was performed with descriptive statistics to characterize patient groups and with correlation analysis to investigate item linkage. The 95% confidence intervals of mean values (CI) were used to test for significant differences between groups.

We analyzed 1557 consecutive geriatric patients: 401 patients (25.8%) had normal cognitive function (MMSE > 26 pts), 592 patients (38.0%) had mild cognitive dysfunction (MMSE 20–26 pts), 285 patients (18.3%) had moderate cognitive impairment (MMSE 11–19 pts) and 279 patients (17.9%) had severe cognitive dysfunction (MMSE < 11 pts). Mean MMSE was 19.4 points. Mean age was 81.6 years, mean body height was 1.63 m, mean body weight was 69.0 kg, mean BMI was 25.9 kg/m2. Of the patients, 17.7% were overweight (BMI > 30 kg/m2), 74% had normal weight (BMI 20–30 kg/m2) and 7.9% were underweight (BMI < 20 kg/m2). Mean FM was 19.3 kg, mean FMI was 7.3 kg/m2, mean FFM was 49.8 kg and mean FFMI was 18.7 kg/m2 (for more details see Table 1).

n Correlation analysis MMSE showed a minor but significant correlation with body weight (r = 0.12, p < 0.001), BMI (r = 0.11, p < 0.001), FM (r = 0.12, p < 0.001) and FMI (r = 0.11, p < 0.001). There was also a very minor but significant correlation with FFM (r = 0.07, p < 0.05) and FFMI (r = 0.07, p < 0.05).

n Characteristics of subjects without cognitive dysfunction A total of 401 subjects (25.8%) had no measurable cognitive dysfunction with MMSE > 26 points. With 80.7 years (95% CI: 80.05–81.25), they were slightly but significantly younger than the entire group (81.6 y; 95% CI: 81.31–81.97). The mean body weight of 70.3 kg (95% CI: 68.81–71.73) was not different from the whole group (69.0 kg; 95% CI: 68.23– 69.70). Accordingly the BMI of 26.3 kg/m2 (95% CI: 25.81–26.79) was not different from the entire group (25.9 kg/m2; 95% CI: 25.68–26.17). Also FM, FMI, FFM and FFMI showed no significant differences compared to the entire study population (for further details see Table 1).

n Characteristics of subjects with mild cognitive dysfunction Mild cognitive dysfunction with MMSE of 20–26 points was assessed in 592 subjects (38.0%). With a

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mean age of 81.2 years (95% CI: 80.64–81.71), they showed no significant difference compared to the group without cognitive dysfunction or to the entire study group. Mean body weight was 70.6 kg (95% CI: 69.31–71.78) and showed no significant difference to the cognitive normal or the entire study population. Mean BMI was 26.4 kg/m2 (95% CI: 25.97–26.79) and was not different from the cognitive normal or the entire group. Also FM, FMI, FFM and FFMI showed no significant differences compared to the entire study population or the group without cognitive dysfunction.

95% CI: 7.29–8.04) cognitive dysfunction. The FFM of the patients with severe cognitive dysfunction (48.4 kg; 95% CI: 47.34–49.53) was significantly lower than in subjects with mild (50.9 kg; 95% CI: 50.03–51.66) cognitive dysfunction, but did not differ significantly from subjects with moderate and no cognitive dysfunction (Figs. 1–3). Mean FFMI was 18.3 kg/m2 (95% CI: 17.98–18.57) and differed signif-

n Characteristics of subjects with moderate cognitive dysfunction A total of 285 subjects (18.3%) had moderate cognitive dysfunction with MMSE of 11–19 points. With a mean age of 82.6 years (95% CI: 81.92–83.35) these subjects were slightly older than those with no or mild cognitive dysfunction, but did not differ from the entire group. The mean body weight of 67.1 kg (95% CI: 65.46–68.75) was significantly lower than in the group with mild (70.6 kg; 95% CI: 69.31–71.78) or no (70.3 kg; 95% CI: 68.81–71.73) cognitive dysfunction. The BMI was 25.5 kg/m2 (95% CI: 24.98–26.08) and not significantly lower than in the other groups. Likewise, FM, FMI, FFM and FFMI were not significantly different from subjects without cognitive dysfunction or from the entire study population.

Fig. 1 Body mass index (BMI) and cognitive function (MMSE)

n Characteristics of subjects with severe cognitive dysfunction Finally, 279 subjects (17.9%) had severe cognitive dysfunction with MMSE < 11 points. With a mean age of 83.3 years (95% CI: 82.21–83.86) they were significantly older than the subjects with mild (81.2 y; 95% CI: 80.64–81.71) and no (80.7 y; 95% CI: 80.05–81.25) cognitive dysfunction. The mean body weight was 65.7 kg (95% CI: 64.07–67.24) and significantly lower than in the group with mild (70.6 kg; 95% CI: 69.31–71.78) and no (70.3 kg; 95% CI: 68.81–71.73) cognitive dysfunction. The mean BMI of 24.8 kg/m2 (95% CI: 24.31–25.35) was significantly lower than in the group with mild (26.4 kg/m2; 95% CI: 25.97–26.79) and without (26.3 kg/m2; 95% CI: 25.81–26.79) cognitive dysfunction. Mean FM of 17.2 kg (95% CI: 16.16–18.22) was significantly lower than in the group with mild (20.0 kg; 95% CI: 19.16– 20.77) and no (20.4 kg; 95% CI: 19.42–21.39) dysfunction. The FMI of 6.6 kg/m2 (95% CI: 6.15–6.95) was significantly lower than in the group with mild (7.5 kg/m2; 95% CI: 7.20–7.81) and no (7.7 kg/m2;

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Fig. 2 Fat mass index (FMI) and cognitive function (MMSE)

Fig. 3 Fat-free mass index (FFMI) and cognitive function (MMSE)


icantly from FFMI of subjects with mild cognitive dysfunction (19.0 kg/m2; 95% CI: 18.74–19.22), but did not differ from subjects with moderate or no cognitive dysfunction. These differences remained significant after correction for age. In conclusion there was a significant difference in body weight, BMI, FM and FMI, but not in FFM and FFMI between the cognitive normal patients and the patients with severe cognitive dysfunction. Patients with severe cognitive dysfunction had a 4.6 kg (6.5%) lower body weight, a 1.5 kg/m2 (5.7%) lower BMI, a 3.2 kg (15.7%) lower FM, and a 1.1 kg/m2 (14.3%) lower FMI. The 1.6 kg (3.2%) lower FFM and the 0.4 kg/m2 (2.1%) lower FFMI was not significantly different (for more details see Table 1).

n Gender-related analysis As we observed a significant distribution difference of female and male subjects in the groups with severe and no cognitive dysfunction, all data were also analyzed separately for female and male subjects.

n Female subjects Female subjects showed similar differences as the entire group. There was a significant difference in body weight, BMI, FM, FMI and FFM, but not FFMI between the cognitive normal patients and the patients with severe cognitive dysfunction. Female patients with severe cognitive dysfunction had a 6.1 kg (9.0%) lower body weight, a 1.7 kg/m2 (6.5%) lower BMI, a 3.7 kg (17.6%) lower FM, a 1.2 kg/m2 (14.8%) lower FMI and a 2.5 kg (5.3%) lower FFM than patients without cognitive impairment. The 0.5 kg/m2 (2.7%) lower FFMI was not significant (see Table 2).

n Male subjects Although in this study male subjects with severe cognitive dysfunction had a 5.2 kg (6.6%) lower body weight than male subjects with normal cognitive function, there were no significant differences in weight, BMI, FM, FMI or FFMI compared to subjects with normal cognitive function. Only FFM was 4.2 kg (7.0%) significantly reduced (see Table 3). Male subjects had a significantly higher body weight but not BMI than female subjects. FM and FMI were significantly lower than in female subjects in all groups. FFM and FFMI of male subjects were significantly higher than in all groups of female subjects (see Tables 2 and 3).

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Discussion This is the first study investigating body composition in relation to the degree of cognitive dysfunction in geriatric patients. Despite the fact that these are cross-sectional data, they clearly indicate that geriatric patients with cognitive dysfunction lose body weight in relation to the degree of cognitive dysfunction. This finding is supported by several other studies [11, 46, 47]. In a recent study by Guérin et al., the authors observed different modes of weight loss in 395 patients with Alzheimer disease. 33.4% of the patients had a slow progressing weight loss with more than 4% loss in body weight over one year, while 10.2% of the patients had a dramatic weight loss of more than 5 kg in one year [47]. In this study one risk factor for slow progressing weight loss was the Reisberg score, which is closely correlated to cognitive dysfunction. In our study, subjects with severe cognitive dysfunction had a 6.5% lower body weight and a 15.7% lower fat mass than subjects with normal cognitive function. The average weight difference of 4.6 kg was predominantly due to loss of FM (66%) and only to a minor degree due to loss of FFM (34%), although the study population had on average 28% FM and 72% FFM. Loss of FFM, which mainly consists of muscle mass, could be due to muscle atrophy, following motor impairment and decline of functional capacity. The data of this study indicate that loss of body weight of subjects with severe cognitive dysfunction is mainly loss of fat mass, which is a further proof of weight loss as a consequence of low energy intake or imbalance of energy requirement and energy intake. In the gender-related analysis, most differences between male subgroups were not significant because of the smaller number of subjects but certainly also because the weight differences between the subgroups were lower. Thus, we conclude that women with severe cognitive dysfunction lose more body weight than men do, which was already shown in small longitudinal studies [19, 35] and a small cross-sectional study [48]. In addition, we can conclude that women seem to lose more fat mass (FM) than men, which was also shown in the previously mentioned study and another small cross-sectional study [48, 49]. Possible mechanisms of these genderrelated differences are not clear. One possible explanation could be that elderly women with cognitive impairment often are widows without a husbandcaregiver, who could provide them with adequate food. Whereas elderly men often still have wives, who provide them with sufficient food and care. This would fit with other studies resuming that especially patients with dementia who live alone

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1557 (100) 416 (26.7) 1141 (73.3) 81.6 ± 6.6 (81.31–81.97) 19.4 ± 9.3 1.63 ± 0.09 (1.624–1.633) 69.0 ± 14.9 (68.23–69.70) 25.9 ± 4.9 (25.68–26.17) 19.3 ± 9.8 (18.81–19.78) 7.3 ± 3.7 (7.11–7.48) 49.8 ± 9.8 (49.35–50.32) 18.7 ± 2.8 (18.55–18.83)

n (%) Male, n (%) Female, n (%) Age, years, mean ± SD (95% CI) MMSE, pts, mean ± SD Body height, m, mean ± SD (95% CI) Body weight, kg, mean ± SD (95% CI) BMI, kg/m2 mean ± SD (95% CI) FM, kg, mean ± SD (95% CI) FMI, kg/m2 mean ± SD (95% CI) FFM, kg, mean ± SD (95% CI) FFMI, kg/m2 mean ± SD (95% CI)

1141 (100) 82.2 ± 6.5 (81.83–82.57) 19.9 ± 9.0 1.60 ± 0.07 (1.594–1.603) 66.2 ± 14.4 (65.35–67.02) 25.9 ± 5.2 (25.58–26.18) 19.8 ± 10.2 (19.24–20.43) 7.7 ± 3.9 (7.52–7.97) 46.5 ± 7.5 (46.06–46.93) 18.2 ± 2.7 (18.04–18.35)

n (%) Age, years, mean ± SD (95% CI) MMSE, pts, mean ± SD Body height, m, mean ± SD (95% CI) Body weight, kg, mean ± SD (95% CI) BMI, kg/m2 mean ± SD (95% CI) FM, kg, mean ± SD (95% CI) FMI, kg/m2 mean ± SD (95% CI) FFM, kg, mean ± SD (95% CI) FFMI, kg/m2, mean ± SD (95% CI)

416 (100) 80.1 ± 6.6 (79.46–80.74) 18.0 ± 9.9 1.71 ± 0.08 (1.706–1.721) 76.6 ± 13.5 (75.32–77.91) 26.6 ± 4.0 (25.67–26.45) 17.8 ± 8.2 (17.02–18.60) 6.1 ± 2.8 (5.79–6.33) 59.0 ± 9.4 (58.10–59.91) 20.1 ± 2.7 (19.80–20.32)

n (%) Age, years, mean ± SD (95% CI) MMSE, pts, mean ± SD Body height, m, mean ± SD (95% CI) Body weight, kg, mean ± SD (95% CI) BMI, kg/m2, mean ± SD (95% CI) FM, kg, mean ± SD (95% CI) FMI, kg/m2, mean ± SD (95% CI) FFM, kg, mean ± SD (95% CI) FFMI, kg/m2, mean ± SD (95% CI)

* Significant difference to subjects without cognitive dysfunction (MMSE > 26)

All MMSE 0–30

Cognitive dysfunction MMSE range

Table 3 Male subjects’ characteristics


All MMSE 0–30


Table 2 Female subjects’ characteristics


All MMSE 0–30


Table 1 Subjects’ characteristics

90 (21.6) 80.0 ± 6.4 (78.68–81.31) 28.0 ± 0.9 1.72 ± 0.08 (1.700–1.733) 78.3 ± 15.4 (75.10–81.44) 26.5 ± 4.4 (25.55–27.37) 18.5 ± 9.4 (16.57–20.47) 6.3 ± 3.2 (5.61–6.93) 60.3 ± 10.6 (58.08–62.45) 20.4 ± 2.8 (19.79–20.94)

No MMSE > 26

311 (27.2) 80.9 ± 6.1 (80.19–81.54) 28.1 ± 1.0 1.61 ± 0.07 (1.601–1.616) 68.0 ± 14.0 (66.43–69.54) 26.3 ± 5.1 (25.69–26.83) 21.0 ± 10.2 (19.82–22.09) 8.1 ± 3.9 (7.64–8.51) 47.1 ± 7.0 (46.31–47.86) 18.2 ± 2.5 (17.92–18.48)

No MMSE > 26

401 (100) 90 (22.4) 311 (77.6) 80.7 ± 6.1 (80.05–81.25) 28.1 ± 1.0 1.63 ± 0.08 (1.624–1.641) 70.3 ± 15.0 (68.81–71.73) 26.3 ± 5.0 (25.81–26.79) 20.4 ± 10.1 (19.41–21.39) 7.7 ± 3.8 (7.29–8.04) 50.0 ± 9.7 (49.09–50.98) 18.7 ± 2.7 (18.42–18.96)

No MMSE > 26

152 (36.5) 79.2 ± 7.0 (78.09–80.33) 23.2 ± 2.2 1.72 ± 0.07 (1.710–1.733) 78.5 ± 13.5 (76.35–80.63) 26.5 ± 4.2 (25.82–27.15) 18.2 ± 8.6 (16.86–19.58) 6.1 ± 2.9 (5.68–6.60) 60.5 ± 9.2 (59.04–61.97) 20.4 ± 2.7 (19.98–20.85)

Mild MMSE 20–26

440 (38.6) 81.9 ± 6.4 (81.25–82.44) 23.4 ± 2.0 1.60 ± 0.07 (1.596–1.610) 67.8 ± 15.0 (66.40–69.20) 26.3 ± 5.4 (25.84–26.84) 20.6 ± 10.4 (19.59–21.54) 8.0 ± 4.0 (7.61–8.35) 47.5 ± 8.1 (46.75–48.27) 18.5 ± 2.9 (18.21–18.75)

Mild MMSE 20–26

592 (100) 152 (25.7) 440 (74.3) 81.2 ± 6.6 (80.64 ± 81.71) 23.4 ± 2.1 1.63 ± 0.09 (1.626–1.641) 70.6 ± 15.3 (69.31–71.78) 26.4 ± 5.1 (25.97–26.79) 20.0 ± 10.0 (19.16–20.77) 7.5 ± 3.8 (7.20–7.81) 50.9 ± 10.2 (50.03–51.66) 19.0 ± 3.0 (18.74–19.22)

Mild MMSE 20–26

80 (19.2) 80.2 ± 5.8 (78.96–81.51) 15.9 ± 2.6 1.71 ± 0.07 (1.693–1.722) 75.3 ± 12.3 (72.64–78.03) 25.7 ± 3.4 (24.99–26.49) 17.3 ± 7.5 (15.67–18.95) 5.9 ± 2.4 (5.36–6.43) 58.1 ± 8.7 (56.21–60.03) 19.9 ± 2.5 (19.33–20.44)

Moderate MMSE 11–19

205 (18.0) 83.6 ± 6.0 (82.75–84.40) * 16.2 ± 2.4 1.59 ± 0.08 (1.574–1.596) * 63.9 ± 13.5 (62.04–65.74) * 25.5 ± 5.1 (24.75 –26.15) 18.9 ± 9.9 (17.51–20.21) 7.5 ± 3.9 (6.98–8.05) 45.2 ± 6.8 (44.25–46.10) * 18.0 ± 2.4 (17.65–18.32)


285 (100) 80 (28.1) 205 (71.9) 82.6 ± 6.2 (81.92–83.35) * 16.1 ± 2.5 1.62 ± 0.09 (1.609–1.631) 67.1 ± 14.2 (65.46–68.75) * 25.5 ± 4.7 (24.98–26.08) 18.4 ± 9.3 (17.35–19.50) 7.1 ± 3.6 (6.64–7.48) 48.8 ± 9.4 (47.72–49.90) 18.5 ± 2.6 (18.22–18.82)


94 (22.6) 81.6 ± 6.7 (80.28–82.97) 1.7 ± 3.3 1.70 ± 0.08 (1.685–1.719) 73.1 ± 11.4 (70.83–75.42) 25.3 ± 3.7 (24.52–26.03) 17.0 ± 6.9 (15.57–18.36) 5.9 ± 2.5 (5.39–6.39) 56.1 ± 8.3 (54.39–57.74) * 19.4 ± 2.6 (18.84–19.87)

Severe MMSE < 11

185 (16.2) 83.8 ± 7.1 (82.73–84.77) * 2.1 ± 3.7 1.58 ± 0.08 (1.573–1.595) * 61.9 ± 13.0 (59.99–63.73) * 24.6 ± 4.7 (23.93–25.28) * 17.3 ± 9.6 (15.92–18.69) * 6.9 ± 3.8 (6.34–7.42) * 44.6 ± 7.1 (43.53–45.59) * 17.7 ± 2.4 (17.39–18.07)

Severe MMSE < 11

279 (100) 94 (33.7) 185 (66.3) 83.3 ± 7.0 (82.21–83.86) * 2.0 ± 3.6 1.62 ± 0.10 (1.612–1.635) 65.7 ± 13.5 (64.07–67.24) * 24.8 ± 4.4 (24.31–25.35) * 17.2 ± 8.8 (16.16–18.22) * 6.6 ± 3.4 (6.15–6.95) * 48.4 ± 9.3 (47.34–49.53) 18.3 ± 2.5 (17.98–18.57)

Severe MMSE < 11

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have an increased risk for malnutrition [50] and that caregiver burden predicts weight loss in Alzheimer disease [11]. Only men with severe cognitive dysfunction had a significantly reduced FFM. Possible explanations for this would be decreased physical activity with consecutive muscle atrophy in demented males or a different mode of weight loss in male subjects, which has been shown by studies on intentional weight loss in obesity [51]. Mean BMI in all tested groups were above the cut-off value of < 22 kg/m2 predicting risk for malnutrition. This means that a significant weight loss is observed in subjects with reduced MMSE values even before overt malnutrition becomes apparent. As men also develop sarcopenia prior to overt malnutrition as classically diagnosed by the BMI, a cognitive decline per se is a risk factor for weight loss and specific body composition changes. As nutritional interventional strategies promise the best effect when started early, a special focus on body weight, body weight changes, as well as body composition analysis in elderly subjects seems warranted.

n Limitations There are several limitations of this study. The first is its cross-sectional character. Cross-sectional data cannot show weight loss over the time. This weakness is partly compensated by the considerable number of study participants. Second, data about the exact differential diagnosis of the reduced MMSE are missing. Yet, it is most likely that patients in the group with moderate and severe cognitive dysfunction mainly suffered from dementia. The group with mild cognitive dysfunction is certainly a mixed group, suffering from dementia, depression, delirium and other forms of cognitive impairment. In further studies it would be interesting to compare weight loss in patients with different causes of cognitive dysfunction, presuming that weight loss in middle

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and late stage dementia is not only a problem in patients with Alzheimer disease.

Conclusion Weight loss is a frequent side effect of dementia and is closely related to the degree of cognitive dysfunction. Malnutrition and weight loss is known to worsen the outcome of elderly patients. Although there are only single, small numbered studies showing effectiveness of nutritional interventions in dementia [49, 52], expert opinion and extrapolation of other study-findings call for action in the sense of routine screening of nutritional state in dementia and early interventional strategies. Interventions should be planned with emphasis on supporting and increasing energy intake by means of optimizing meal ambiance, meal supply and assistance, energy density of meals and supplementation with oral nutritional supplements. Thus, the key messages are: • Patients with severe cognitive dysfunction have a lower body weight and BMI because they lose substantial amounts of body weight during the ongoing disease. • Female subjects with cognitive dysfunction lose more weight than males. • Female subjects with cognitive dysfunction predominantly lose fat mass. • Male subjects with cognitive dysfunction predominantly lose fat-free mass. • Further studies should consider gender-related differences in body composition and weight loss. • Patients with cognitive dysfunction should be regularly screened for malnutrition to enable early nutritional intervention to prevent relevant weight loss. " Conflict of interest The author received lecture honorariums from Fresenius Kabi, Pfrimmer-Nutricia, Merz-Pharma. In spite of this possible conflict of interest, the contribution is impartial and product neutral.

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