Impact of physical activity and sedentarism on hydration status and liquid intake in Spanish older adults. The PHYSMED study

Raquel Aparicio-Ugarriza¹, Raquel Luzardo-Socorro¹, Gonzalo Palacios^1,2, María del Mar Bibiloni^2,3, Alicia Julibert^2,3, Josep Antoni Tur^2,3 and Marcela González-Gross^1,2

¹ImFINE Research Group, Spain. Faculty of Physical Activity and Sport Sciences (INEF). Technical University of Madrid. Madrid, Spain.
²CIBEROBN (Physiopathology of Obesity and Nutrition CB12/03/30038). Madrid, Spain.
³Research Group on Community Nutrition and Oxidative Stress (NUCOX). University of the Balearic Islands. Palma, Balearic Islands. Spain

This study took place with the financial support of the Spanish Ministry of Economy and Competitiveness-Instituto de Salud Carlos III (PI11/01791), CIBEROBN (CB12/03/30038) and the European Hydration Institute (E131115081).

ABSTRACT

Introduction: Data on hydration status in older adults are scarce and there are very few studies focusing on the impact of physical activity (PA) on drinking behavior.
Objective: To assess the impact of physical activity and sedentarism on fluid intake in Spanish elderly.
Methods: 433 non-institutionalized Spanish older adults (58% females), aged 55-88 years, volunteered for the PHYSMED study. PA data were obtained by means of the Minnesota and EXERNET questionnaires. Population was divided into four groups: ILS (inactive and low sedentary), IHS (inactive and high sedentary), ALS (active and low sedentary) and AHS (active and high sedentary). Serum from fasting blood samples was analysed for osmolarity.
Results: The mean of total liquid intake was 1,751 ± 628 mL/d. Significant differences were observed for total liquid intake between ILS/ALS and IHS/ALS (p < 0.001). ALS subjects consumed a higher amount of beverages such as water, juice, milk, coffee, sport drink, beer, wine and distilled drinks than the other PA groups. There was a significant difference for water intake between PA groups (p < 0.01). Serum osmolarity values were within references ranges in all subjects, and there was a significant difference between PA groups (p < 0.01).
Conclusions: Spanish older adults meet the DACH recommendations set by the German, Austrian and Swiss nutrition societies' liquid intake recommendations in the mean independently of PA and sedentary level. All participants are within reference ranges of serum osmolarity. Subjects in the active and low sedentary group consumed higher amounts of water and other beverages than in the other PA groups.

Key words: Beverages. Water intake. Physical activity. Elderly. Sedentary lifestyle.

Introduction

Quantification of water and beverage intake is an emerging topic in nutritional sciences as the optimal functioning of our body requires a proper hydration level (1,2). Likewise, water intake and hydration status have recently gained attention as one of the many and potentially manageable factors associated with disease development and wellbeing (3). Water is an essential nutrient for human body and major key to survival (4).

However, the current lack of a hydration assessment gold standard greatly impedes attempts to link water intake and negative health outcomes as well as to make public dietary guidelines (5,6). The questions "what do you drink", "how much do you drink per day" and "how much fluids do you drink" are frequently omitted in the common dietary questionnaires, and recommendations for beverage intake are, or were until recently, missing in most "food pyramids" (7,8).

Maintaining an adequate fluid balance is an essential component of health at every stage of life, especially in elderly population since older adults are at higher risk of developing dehydration for various physiological reasons (7). Moreover, in elderly individuals, adequate fluid consumption has been associated with fewer falls, lower rates of constipation and laxative use, as well as better rehabilitation outcomes in orthopedic patients (9-11). Also, dehydration can precipitate emergency hospitalization and increases the risk of repeated hospitalizations (12).

Elderly may frequently meet difficulties in gaining access to beverages due to decreased mobility, visual problems, swallowing disorders, cognitive alterations, use of drugs and fear of incontinence (7). Numerous factors such as high ambient temperature and humidity levels, heat stress and physical activity can influence water needs (13). Therefore, adequate intake of fluids must be increased in relation to these conditions (1). High temperature and humidity also might provoke exacerbated dehydration, but there is limited information about the effects of seasonality and climate on water intake (14).

The benefits of regular physical activity (PA) on health and disease prevention are well recognized (15). PA reduces both morbidity and mortality and can minimize the physiological effects of an otherwise sedentary lifestyle increasing the active lifespan (16,17). On the other hand, prolonged sitting has emerged as a risk factor for early mortality and has deleterious health effects. Nevertheless, sedentarism has not been included in the past in studies about physical activity (17). In spite of the powerful benefits of PA and optimal hydration status, there are only a few studies analysing together fluid intake, PA and sedentarism in elderly population. Hence, these parameters are a key point to define public health recommendations.

The aim of this study was to assess the impact of physical activity and sedentarism on fluid intake in Spanish older adults.

Methods

The present study was based on a cross-sectional multicenter study aiming at identifying cardiovascular risk factors in sedentary and active elderly subjects. The survey was conducted from April 2013 to May 2014 in Madrid and Majorca (Spain). Participants were voluntaries recruited at health centers, sport federations, sport facilities and municipal clubs located at Madrid and Majorca. A total of 433 subjects, 186 male (43%) and 247 females (57%) aged 55 to 88 years old were included in this study. The exclusion criteria were age under 55, being institutionalized, suffering from a physical or mental illness that would have limited their participation in the physical fitness tests or their ability to respond to the questionnaires, or drug intake for clinical research.

All measurements at each institution were conducted according to the survey protocol. The study was performed according to the principles established in the Declaration of Helsinki and approved by the Ethical Committee of the Technical University of Madrid. Written informed consent was obtained from all participants.

HYDRATATION QUESTIONNAIRE

A hydration questionnaire was developed by the Research Group based on food-frequency and eating habits questionnaires published in the literature (18,19), taking into account the modern beverage market.

The questionnaire is divided into two parts. The first part includes questions about the different types of fluids consumed one day before the questionnaire was filled out. The second part records the fluid intake during a normal week for each beverage type. The beverages included were: water, juice, soft drinks, diet drinks, milk, shake, coffee, tea or infusions, sport drinks, beer, wine and distilled drinks.

PHISYCAL ACTIVITY AND SEDEMTARISM ASSESSMENT

PA was assessed by means of two validated self-reported questionnaires; the Minnesota Leisure Time Physical Activity Questionnaire measuring the activity during the previous year, and the EXERNET questionnaire, both of them validated for the Spanish population (20-22).

The Minnesota questionnaire includes diverse physical activities and participants are asked about PA duration, weekly and monthly frequencies. Time for each activity was expressed in minutes per day (min/d). On the other hand, the Exernet Questionnaire included four questions about regular physical activity duration, time spent walking, time spent doing housework and time spent sitting per day. All questions were bounded and answers included six options which were classified as less than 1 hour, between 1 and 2 hours, between 2 and 3 hours, between 3 and 4 hours, between 4 and 5 hours and more than 5 hours. The only exception was for regular physical activity duration. All activities were recorded in min/day.

In order to compare between different levels of PA and sedentarism, our population was classified in 4 groups: inactive and low sedentary (ILS), inactive and high sedentary (IHS), active and low sedentary (ALS) and active and high sedentary (AHS) taking into account cluster analyses set by Aparicio-Ugarriza et al. (23).

Fasting blood samples were collected from each participant by standard venipuncture on vacuum Vacutainer^® tubes in Madrid and Palma (Majorca), at the biochemical laboratory of the High Sports Council, Madrid, Son Espases Hospital and University of the Balearic Islands, Palma (Majorca), respectively. Serum was separated in 1 mL eppendorfs and was processed to analyse osmolarity using an osmometer Osmo Station OM-6050 (Menarini Diagnostics, Florence, Italy, CV ≤ 1%).

STATISTICAL ANALYSIS

Descriptive values are shown as mean ± standard deviation. One-way ANOVA was performed to analyse the differences between serum osmolarity, total liquid intake and beverages consumption and post hoc analyses were conducted with Bonferroni adjustment according to the PA and sedentarism groups (ALS, AHS, IHS and ILS).

All analysis were performed using the Statistical Package for Social Science software (SPSS, version 21.0;SPSS, Chicago, IL, USA) and values of p < 0.05 were considered to be statistically significant.

Results

Table I includes descriptive characteristics of the sample split by sex. Males were heavier and taller than females (p < 0.01) and had a higher BMI (p < 0.05). No differences by sex were observed for mean serum osmolarity.

Figure 1 shows serum osmolarity according to PA groups. All subjects were within reference ranges of serum osmolarity and significant differences were found between PA groups (p < 0.01). After Bonferroni's adjustment, there was a significant difference between IHS and ALS (p < 0.05). The mean higher serum osmolarity was obtained for ALS group (290.97 mOsm/L).

Figure 2 shows the mean (± SD) total liquid intake per day consumed according to PA groups. The ALS group and AHS group consumed 2,056.2 ± 679.6 mL/d and 1,899.9 ± 633.4 mL/d, respectively. On the other hand, the mean of total liquid intake was 1,647.8 ± 569.4 mL/d for ILS group and 1,647.5 ± 597.2 mL/d for IHS group. There were significant differences between ALS and ILS groups and also between ALS and IHS groups (p < 0.001).

Figure 3 shows the mean beverage consumptions per day divided by PA groups. Water was the beverage most consumed for all PA groups and there were significant differences between them (p < 0.01). ALS drank more beverages such as water, juice, milk, coffee, sport drink, beer, wine and distilled drinks than the other PA groups. Significant difference was only observed for water between PA groups (p < 0.01). Moreover, AHS showed a trend to consume more soft and light soft drinks, shake and tea than the other PA groups (non-significant values).

Discussion

The results from this cross-sectional study indicated that the mean of total liquid intake in our sample was high (1,751.3 mL/d, data are not shown) compared with the DACH recommendations set by the German, Austrian and Swiss nutrition societies (DACH) (1,310 mL/d) (24). The ALS group consumed significantly higher amounts of water (p < 0.01) and showed a trend of high consumption of other fluids (NS) than the other PA groups. There were differences (p < 0.01) in serum osmolarity between PA groups. However, despite these differences, all subjects were within serum osmolarity reference ranges.

There is no consensus in the literature regarding water and beverage intake recommendations. We compared to the DACH recommendations because they split recommendations into water from beverages and from food specifically for people aged over 65 years. In contrast, the World Health Organization in 2005 (25) recommended 2.2 L/d and 2.9 L/d for females and males, respectively. The European Food Safety Authority in 2010 (26) established 2 L/d for females and 2.5 L/d for males as the total water intake without differentiating into water from food and beverages. Other authors consider that the minimum water intake for drinking water and beverages must range from 1.5-1.8 L/d, although some adaptations are established depending on age, sex and medications (7).

Likewise, the best way of measuring hydration in humans is still a general controversy (27) because there are different methods such as estimates of water balance (thirst rating, total water intake and output or body weight changes), hydration markers (plasma or urine osmolarity) and total body water measurements by bioelectrical impedance or isotope dilution (28). In our study, we measured serum osmolarity as it is closely controlled and rarely varies by more than 2% around a set point of 280-290 mOsm/L (1). According to Jequier et al. (1), a basal mean value of 287 mOsm/L is maintained in well-hydrated individuals. In our sample, the mean of serum osmolarity levels was 289 mOsm/L for both sexes, though a significant difference was obtained between PA groups (p < 0.01).

On the other hand, in our study, water was the beverage most consumption in all PA groups and a significant difference was obtained between them (p < 0.01) followed by light soft drinks. In their study, Zizza et al. (29) found that water was the most consumption, followed by coffee. De Francisco et al. (30) observed that people with high PA levels drank more fluids compared with those with low PA levels. We found the same patterns in our study since both active groups (ALS and AHS) had higher intakes than both inactive groups.

Furthermore, we found that ALS subjects drank higher amounts of water, juice, milk, coffee, sport drinks, beer, wine and distilled drinks than the other PA groups. Additionally, AHS consumed more soft and light soft drinks, milk shakes and tea than the other PA groups.

STRENGTHS AND LIMITATIONS

On the other hand, this study has also several limitations. First, it is directly related to the intrinsic nature of the Exernet Questionnaire, in which for several questions only closed answers were available and also for the subjectiveness of the physical activity and sedentary questionnaires. Secondly, our study has a cross-sectional design, therefore impeding the determination of cause-effect relationships.

Conclusions

The mean of Spanish older adults meets DACH liquid intake recommendations independently of physical activity and sedentary level; furthermore, all participants are within reference ranges of serum osmolarity. Subjects in the active and low sedentary group consumed higher amounts of water and other beverages than in the other PA groups. Physical activity and sedentarism should be considered to obtain a holistic approach to beverage intake and hydration status in future researches. Additionally, longitudinal studies are needed in order to establish behavior patterns.

Acknowledgements

The authors are grateful to all the subjects who took part in the PHYSMED study and to all the researchers who set up the data for further analysis.

References

1. Jequier E, Constant F. Water as an essential nutrient: The physiological basis of hydration. Eur J Clin Nutr 2010;64(2):115-23.         [ Links ]

2. Gandy J. Water intake: Validity of population assessment and recommendations. Eur J Nutr 2015 Jun;54(Suppl. 2):11-6.         [ Links ]

3. Casado A, Ramos P, Rodríguez J, Moreno N, Gil P. Types and characteristics of drinking water for hydration in the elderly. Crit Rev Food Sci Nutr 2015;55(12):1633-41.         [ Links ]

4. Pedrero-Chamizo R, González Groos M. Importancia del consumo de líquidos en adolescentes deportistas. Alim Nutri, Salud 2008;15(1):19-28.         [ Links ]

5. Munoz CX, McKenzie AL, Armstrong LE. Optimal hydration biomarkers: Consideration of daily activities. Obes Facts 2014;7(Suppl. 2):13-8.         [ Links ]

6. Marshall TA, Eichenberger Gilmore JM, Broffitt B, Levy SM, Stumbo PJ. Relative validation of a beverage frequency questionnaire in children ages 6 months through 5 years using 3-day food and beverage diaries. J Am Diet Assoc 2003;103(6):714,20;discussion 720.         [ Links ]

7. Lafontan M, Visscher TL, Farpour-Lambert N, Yumuk V. Opportunities for intervention strategies for weight management: Global actions on fluid intake patterns. Obes Facts 2015;8(1):54-76.         [ Links ]

8. Gonzélez-Gross M, Gómez-Lorente JJ, Valtuena J, Ortiz JC, Meléndez A. The "healthy lifestyle guide pyramid" for children and adolescents. Nutr Hosp 2008;23(2):159-68.         [ Links ]

9. Mentes JC, Culp K. Reducing hydration-linked events in nursing home residents. Clin Nurs Res 2003 Aug;12(3):210,25;discussion 226-8.         [ Links ]

10. Simmons SF, Alessi C, Schnelle JF. An intervention to increase fluid intake in nursing home residents: Prompting and preference compliance. J Am Geriatr Soc 2001;49(7):926-33.         [ Links ]

11. Mentes JC, Wakefield B, Culp K. Use of a urine color chart to monitor hydration status in nursing home residents. Biol Res Nurs 2006;7(3):197-203.         [ Links ]

12. Robinson SB, Rosher RB. Can a beverage cart help improve hydration? Geriatr Nurs 2002;23(4):208-11.         [ Links ]

13. Sawka MN, Cheuvront SN, Carter R 3^rd. Human water needs. Nutr Rev 2005;63(6 Pt 2):S30-9.         [ Links ]

14. Westerterp KR, Plasqui G, Goris AH. Water loss as a function of energy intake, physical activity and season. Br J Nutr 2005;93(2):199-203.         [ Links ]

15. Neufer PD, Bamman MM, Muoio DM, Bouchard C, Cooper DM, Goodpaster BH, et al. Understanding the cellular and molecular mechanisms of physical activity-induced health benefits. Cell Metab 2015;22(1):4-11.         [ Links ]

16. Matthews CE, Moore SC, Sampson J, Blair A, Xiao Q, Keadle SK, et al. Mortality benefits for replacing sitting time with different physical activities. Med Sci Sports Exerc 2015;47(9):1833-40.         [ Links ]

17. Biswas A, Oh PI, Faulkner GE, Bajaj RR, Silver MA, Mitchell MS, et al. Sedentary time and its association with risk for disease incidence, mortality, and hospitalization in adults: A systematic review and meta-analysis. Ann Intern Med 2015;162(2):123-32.         [ Links ]

18. ESADE. Study on healthy attitudes and behaviors of the elderly in their hydration. Observatory of behavior: Society and consumption. In: Age and life;2010.         [ Links ]

19. Muckelbauer R, Libuda L, Kersting M. Relative validity of a self-completion 24 h recall questionnaire to assess beverage consumption among schoolchildren aged 7 to 9 years. Public Health Nutr 2010;13(2):187-95.         [ Links ]

20. Elosua R, Marrugat J, Molina L, Pons S, Pujol E. Validation of the Minnesota leisure time physical activity questionnaire in Spanish men. The MARATHOM investigators. Am J Epidemiol 1994;139(12):1197-209.         [ Links ]

21. Elosua R, García M, Aguilar A, Molina L, Covas MI, Marrugat J. Validation of the Minnesota leisure time physical activity questionnaire in Spanish women. Investigators of the MARATDON group. Med Sci Sports Exerc 2000;32(8):1431-7.         [ Links ]

22. Gómez-Cabello A, Pedrero-Chamizo R, Olivares PR, Luzardo L, Juez-Bengoechea A, Mata E, et al. Prevalence of overweight and obesity in non-institutionalized people aged 65 or over from Spain: The elderly EXERNET multi-centre study. Obes Rev 2011;12(8):583-92.         [ Links ]

23. Aparicio-Ugarriza R, Pedrero-Chamizo R, Bibiloni MM, Palacios G, Sureda A, Meléndez A, et al. A classification combining physical activity and sedentarism is a good predictor of physical fitness in people aged over 55 years. The PHYSMED study. J Sports Sci 2016. Submitted.         [ Links ]

24. Deutsche Gesellschaft für Ernährung e.V. Cited January 30^th 2016. Available at: http://www.dge.de/wissensthaft/refernzwerte/wasser/.         [ Links ]

25. Nutrients in drinking water; c2005. Cited January 2016. Available at: http://www.who.int/water_sanitation_health/dwq/nutrientsindw.pdf.         [ Links ]

26. Scientific opinion on dietary reference values for water. Cited November 22^nd 2015. Available at: www.efsa.europa.eu/en/scdocs/scdoc/1459.htm.         [ Links ]

27. Nissensohn M, López-Ufano M, Castro-Quezada I, Serra-Majem L. Assessment of beverage intake and hydration status. Nutr Hosp 2015;31(Suppl. 3):62-9.         [ Links ]

28. Mielgo-Ayuso J, Maroto-Sánchez B, Luzardo-Socorro R, Palacios G, Palacios Gil-Antunano N, EXERNET Study Group, et al. Evaluation of nutritional status and energy expenditure in athletes. Nutr Hosp 2015;31(Suppl. 3):227-36.         [ Links ]

29. Zizza CA, Ellison KJ, Wernette CM. Total water intakes of community-living middle-old and oldest-old adults. J Gerontol A Biol Sci Med Sci 2009;64(4):481-6.         [ Links ]

30. De Francisco ALM, Martínez Castelao A. Estudio bahía 2008: Barómetro de la hidratación de la población española. Revista Nefrología 2010;30(2):220-6.         [ Links ]

Correspondence:
Marcela González-Gross.
ImFine Research Group.
Department of Health and Human Performance.
Faculty of Physical Activity and Sport Science.
Technical University of Madrid.
C/ Martín Fierro, 7.
28040 Madrid, Spain ]]> e-mail: marcela.gonzalez.gross@upm.es