Cold-water or partial-body cryotherapy? Comparison of physiological responses and recovery following muscle damage.

The aim of this study is to compare (a) the physiological responses following cold-water immersion (CWI) and partial-body cryotherapy (PBC) and (b) the effects on recovery following a muscle-damaging protocol (5 × 20 drop jumps). Nineteen healthy males were randomly allocated into either a CWI (10°C for 10 minutes; n = 9) or a PBC (-60°C for 30 seconds, -135°C for 2 minutes; n = 10) group. The physiological variables (thigh muscle oxygen saturation [SmO2 ], cutaneous vascular conductance [CVC], mean arterial pressure [MAP], and local skin temperature) were assessed immediately prior and up to 60 minutes post-treatment (10-minutes intervals). The recovery variables (thigh muscle swelling, maximum voluntary contraction [MVC] of the right knee extensors, vertical jump performance [VJP], and delayed onset of muscle soreness [DOMS]) were measured immediately prior and up to 72 hours post-treatment (24-hours intervals). Compared to PBC values, CVC (at 30 minutes), SmO2 (at 40 minutes), and lower extremity skin temperature (thigh/shin at 60 minutes) were significantly reduced in the CWI group after the treatment (all P < .05). Only lower extremity skin temperature was significantly reduced in the PBC group directly post-treatment (all P < .05). MAP significantly increased in both groups after the treatments (both P < .05). DOMS did not differ between groups. MVC and VJP returned to baseline in both groups after 24 hours (P > .05). CWI had a greater impact on the physiological response compared to PBC. However, both treatments resulted in similar recovery profiles during a 72-hours follow-up period.

Estimation of sweat rates during cycling exercise by means of the closed chamber condenser technology.

BACKGROUND/AIM: Knowledge of local sweating patterns is of importance in occupational and exercise physiology settings. The recently developed closed chamber condenser technology (Biox Aquaflux® ) allows the measurement of evaporative skin water loss with a greater measurement capacity (up to 1325 g/h/m2 ) compared to traditional evaporimeters. The aim of this study was to evaluate the applicability of the Biox Aquaflux® to estimate sweat production during exercise. METHODS: Fourteen healthy subjects performed a 20-min cycle ergometer trial at respectively 55% heart rate (HRreserve and 75% HRreserve . Sweat production was estimated by measuring body weight before and after exercise, by calculating the amount of sweat collected in a patch, and by measuring the water flux (in g/h/m2 ) with the Biox Aquaflux® instrument. RESULTS: The Biox Aquaflux® instrument allowed the follow up of sweat kinetics at both intensities. Correlations between the measurement methods were all significant for the 75% HRreserve trial (with r ranging from 0.68 to 0.76) whilst for the 55% HRreserve a significant relation was detected between the patch method and the Biox Aquaflux® only (with r ranging from 0.41 to 0.79). CONCLUSION: The Biox Aquaflux® instrument is a practical and direct method for the estimation of local sweat rates under field conditions.

Relation between dietary pattern analysis (principal component analysis) and body mass index: a 5-year follow-up study in a Belgian military population.

INTRODUCTION: Increasing body mass index (BMI) has been related to many chronic diseases. Knowledge of nutritional determinants of BMI increase may be important to detect persons at risk. METHODS: A longitudinal prospective study design was used in 805 Belgian soldiers. Daily nutrition was recorded with a validated food-frequency questionnaire. Weight and height were recorded from medical military data and principal component analysis was used to detect dietary patterns. RESULTS: During the 5 years follow-up, mean BMI increased from 25.8 (±3.3) kg/m(2) to 27.1 (±3.6) kg/m(2) (p<0.05). Consequently, the prevalence of being overweight and obesity increased from 46.2% and 9.6% to 51.6% and 19.9% (p<0.05), respectively. Mean (SD) weight gain differed between the BMI categories at baseline with a respective weight gain of 3.8 (±3.1) kg for normal weight at baseline, 4.2 (±3.2) kg for overweight and 5.1 (±3.4) kg for obesity (p for trend <0.05). Three dietary patterns were detected by principal component analysis: Meat, Sweet and Healthy dietary pattern. In energy-unadjusted and adjusted linear regressions, no dietary pattern was associated with BMI increase. CONCLUSIONS: No specific dietary pattern was related to BMI increase. Prevention of obesity should focus on total energy intake at all BMI categories.

Influence of the timing of ultrasound application on the penetration of corticosteroids.

BACKGROUND: The application of ultrasound to enhance the transdermal transport of drugs is often referred to as 'sonophoresis'. In physiotherapy sonophoresis is applied to the skin through two different procedures: (1) the pre-treatment procedure where the skin is treated with ultrasound irradiation prior to the drug application and (2) a simultaneous treatment mode, where the skin is treated with ultrasound during the application of the pharmacologic substance. The aim of this study was to compare the bioavailability of halcinonide in the stratum corneum comparing the ultrasound pre-treatment vs. the simultaneous treatment method. METHODS: The effect of pre and simultaneous ultrasound treatment (1 MHz, 1 W/cm(2)) was evaluated on the halcinonide blanching response using tristimulus colorimetry 2 h after the initial application. RESULTS: Within the evaluation period, only the ultrasound pre-treatment method resulted in a significant blanching response. CONCLUSION: Timing of the ultrasound application seems to influence the availability and percutaneous penetration process and should be taken into account when estimating the ultrasound enhancing effect.

Influence of physical development on start and countermovement jump performance in adolescent sprint athletes.

AIM: The aim of the present study was to describe the effect of physical changes during adolescence on sprint start and countermovement jump (CMJ) performance. METHODS: Twenty-eight girls and 25 boys (15.0±1.6 and 14.7±1.9 years at start respectively) were measured twice with a one year interval. Anthropometric data allowed skeletal muscle mass (SMM) estimation. Athletes performed a 10m sprint tracked from behind by a laser sensor, with starting blocks measuring propulsion forces. CMJ's were performed on a Kistler force plate. RESULTS: Between the two measurement occasions both genders increased in body height, weight and SMM. In girls and boys, impulse during the push-off, block leaving velocity and times at 5 and 10 m improved significantly. In both genders CMJ absolute power increased but not power.kg-1. Only in boys a higher CMJ was registered on occasion 2. For both genders on both occasions, impulse during the push-off correlated with body weight, SMM and CMJ power (r from .46 to .84), and in boys also with CMJ height and CMJ power.kg-1 (r from 0.43 to 0.76). Boys showed CMJ height and power to correlate with 5 and 10 m times (r from -0.42 to -0.79) and with block leaving velocity, however only on the first data collection (r=0.61 and 0.59, respectively). CONCLUSION: Sprint start performance is only partly related to muscular development and CMJ could predict start performance in boys only. Sprint start and CMJ rely on technical skills and, therefore, increasing muscularity should be accompanied with sufficient specific training to allow an optimal transfer to start performance.

Pre-exercise hypohydration prevalence in soccer players: A quantitative systematic review.

Pre-exercise hypohydration can impair soccer performance and has been extensively studied in different soccer populations. Therefore, the aim of this systematic review was to report hypohydration prevalence, measured by blood or urine samples, in different soccer populations based on sex (males and females), performance level (professional and recreational players) and context (training sessions and games). The Pubmed, Web of Science and SPORTDiscus databases were systematically searched until November 2018. Data were pooled to compare hypohydration prevalence between the different subgroups. Following the systematic search selection process, 24 studies were included. The results indicated that overall pre-exercise hypohydration prevalence was 63.3%, 37.4% and 58.8% for urine specific gravity (USG), urine osmolality (U Osm) and urine colour, respectively. Furthermore, no study implemented blood samples to examine hypohydration prevalence in soccer players. The subgroup analyses using USG data indicated that pre-exercise hypohydration prevalence was significantly higher amongst males (66.0%; p = 0.001), professional soccer players (66.2%; p = 0.020) and before a training session (79.6%; p < 0.001). Pre-exercise hypohydration prevalence was 46.8% among female soccer players, 55.6% in recreational soccer players and 41,3% before a game. The subgroup analyses using U Osm data indicated that hypohydration prevalence was significantly higher before a training session (52.6%; p = 0.023). Based on these results, it can be concluded that hypohydration prevalence in soccer players is of major concern. Future research should explore how pre-exercise hydration status can be improved in a sustainable way.

Energy availability and nutrition during a Special Force Qualification Course (Q-Course).

INTRODUCTION: The Special Forces (SF) are an elite military group usually engaged in physically demanding field operations, resulting among others in high daily energy requirements. Optimising energy supply and nutritional requirements is therefore mandatory for success. The aim of this study was to estimate energy availability and nutrition during a Qualification Course (Q-Course) for Belgian SF. METHODS: 21 participants recorded all foods and beverages consumed during four days in a structured food diary. Energy expenditure was measured with an accelerometer and fat mass measured with quadripolar impedance. Energy availability was calculated by the following formula: (energy intake by foods and beverages - energy expenditure for physical activity)/kg FFM/day (FFM, fat-free mass). RESULTS: The mean (SD) total energy expenditure was 4926 kcal/day (238), with a minimum of 4645 kcal/day and a maximum of 5472 kcal/day. The mean (SD) total energy consumption was 4186 kcal/day (842), giving an energy balance ranging from -2005 kcal/day to 1113 kcal/day. The mean (SD) energy availability was 17 kcal/kg FFM/day, with a minimum of 1 kcal/kg FFM/day and a maximum of 44 kcal/kg FFM/day. The mean (SD) intake of carbohydrates was 6.8 g/kg body weight/day (1.5). CONCLUSIONS: During this studied Q-Course, energy intake was not optimal as demonstrated by an overall negative energy balance and low energy availability. High interindividual variations in energy intake were found, highlighting the importance of providing SF members nutritional education.

Tracking of adult adiposity in early, average and late maturing children: a thirty year longitudinal growth study.

AIM: To investigate if predictability of adult adiposity is related to maturation status in youth. METHODS: Data of the longitudinal ''LEGS''-study (N = 550) from 6 to 18 years were used. At 35 years, 59 men and 60 women participated again. Early (EM), average (AM) and late (LM) maturity groups were established, using tertiles of age at peak height velocity (JPA-method). Pearson correlations between the childhood and the adult measurements were calculated. RESULTS: Female sum of 4 skinfolds (Sigma4SF) correlations increase from very low/moderate (6-9 years) to high at 11 years (EM), 15 years (AM) and 17 years (LM). The highest predictability was 65.6% for the Sigma4SF at 14 years in EM. At this age, predictability is 30.3% in AM and 0.8% in LM (P < 0.05). In EM, BMI correlations are moderate/high until 14 yrs (r2 = 0.64 at 13 years), but low until 15 years in LM. Male Sigma4SF correlations are very low/moderate in the three maturity groups. Significant correlation was found in the LM at 16 yrs. Moderate Body Mass index (BMI) correlations are reached at 9 years (LM) and 11 years (EM). At 16 years predictability = 4.9% for BMI in LM males. CONCLUSION: Predictability of adiposity at 35 years is generally better in girls than in boys. A dose-response effect of maturity on adult adiposity is found in girls but not in boys. Interventions to prevent adult obesity might be more effective in females than in males, particularly in EM females.

Relation between sugar-sweetened beverage consumption and micronutrient intake in a prospective study.

Micronutrient dilution following sugar-sweetened beverage (SSB) consumption can lead to a qualitative impoverishment of a dietary pattern. The aim of this prospective study was to investigate the relation between SSB consumption and micronutrients. A total 562 adults were tested in 2002 and 2012 for the same anthropometric, lifestyle and nutritional intake activity parameters. Calcium, iron and magnesium intake decreased with increasing baseline SSB intake, and with increasing SSB consumption during the 10 years. A 100 ml increase in SSB consumption was associated with a 22 mg lower intake of calcium, 0.4 mg of iron and 9 mg of magnesium. There was no relation between vitamins and SSB consumption. In conclusion, there was limited evidence in our study, which suggests SSB have minimal dilutional effect on dietary micronutrient consumption. A major limitation of the present study is that of the original 1569 participants in 2002, 36% returned for participation in 2012.

Evaluation and review of body fluids saliva, sweat and tear compared to biochemical hydration assessment markers within blood and urine.

Evaluating and testing hydration status is increasingly requested by rehabilitation, sport, military and performance-related activities. Besides commonly used biochemical hydration assessment markers within blood and urine, which have their advantages and limitations in collection and evaluating hydration status, there are other potential markers present within saliva, sweat or tear. This literature review focuses on body fluids saliva, sweat and tear compared to blood and urine regarding practicality and hydration status influenced by fluid restriction and/or physical activity. The selected articles included healthy subjects, biochemical hydration assessment markers and a well-described (de)hydration procedure. The included studies (n=16) revealed that the setting and the method of collecting respectively accessing body fluids are particularly important aspects to choose the optimal hydration marker. To obtain a sample of saliva is one of the simplest ways to collect body fluids. During exercise and heat exposures, saliva composition might be an effective index but seems to be highly variable. The collection of sweat is a more extensive and time-consuming technique making it more difficult to evaluate dehydration and to make a statement about the hydration status at a particular time. The collection procedure of tear fluid is easy to access and causes very little discomfort to the subject. Tear osmolarity increases with dehydration in parallel to alterations in plasma osmolality and urine-specific gravity. But at the individual level, its sensitivity has to be further determined.

Effect of oral intake of choline-stabilized orthosilicic acid on hair tensile strength and morphology in women with fine hair.

The appearance of hair plays an important role in people's overall physical appearance and self-perception. Silicon (Si) has been suggested to have a role in the formation of connective tissue and is present at 1-10 ppm in hair. Choline-stabilized orthosilicic acid ("ch-OSA") is a bioavailable form of silicon which was found to improve skin microrelief and skin mechanical properties in women with photoaged skin. The effect of ch-OSA on hair was investigated in a randomized, double blind, placebo-controlled study. Forty-eight women with fine hair were given 10 mg Si/day in the form of ch-OSA beadlets (n = 24) or a placebo (n = 24), orally for 9 months. Hair morphology and tensile properties were evaluated before and after treatment. Urinary silicon concentration increased significantly in the ch-OSA supplemented group but not in the placebo group. The elastic gradient decreased in both groups but the change was significantly smaller in the ch-OSA group (-4.52%) compared to placebo group (-11.9%). Break load changed significantly in the placebo group (-10.8%) but not in the ch-OSA supplemented group (-2.20%). Break stress and elastic modulus decreased in both groups but the change was smaller in the ch-OSA group. The cross sectional area increased significantly after 9 months compared to baseline in ch-OSA supplemented subjects but not in the placebo group. The change in urinary silicon excretion was significantly correlated with the change in cross sectional area. Oral intake of ch-OSA had a positive effect on tensile strength including elasticity and break load and resulted in thicker hair.

Stability of physical activity, fitness components and diet quality indices.

BACKGROUND: Regular physical activity (PA), a high level of fitness and a high diet quality are positively associated with health. However, information about stability of fitness components and diet quality indices is limited. This study aimed to evaluate stability of those parameters. METHODS: This study includes 652 adults (men=57.56 (10.28) years; women=55.90 (8.34) years at follow-up) who participated in 2002-2004 and returned for follow-up at the Policy Research Centre Leuven in 2012-2014. Minutes sport per day and Physical activity level (PAL) were calculated from the Flemish Physical Activity Computerized Questionnaire. Cardiorespiratory fitness (CRF), morphological fitness (MORF; body mass index and waist circumference) and metabolic fitness (METF) (blood cholesterol and triglycerides) were used as fitness components. Diet quality indices (Healthy Eating Index-2010 (HEI), Diet Quality Index (DQI), Mediterranean Diet Score (MDS)) were calculated from a diet record. Tracking coefficients were calculated using Pearson/Spearman correlation coefficients (rPearson) and intra-class correlation coefficients (rICC). RESULTS: In both men (rPearson&ICC=0.51) and women (rPearson=0.62 and rICC=0.60) PAL showed good stability, while minutes sport remained stable in women (rPearson&ICC=0.57) but less in men (rPearson&ICC=0.45). Most fitness components remained stable (r⩾0.50) except some METF components in women. In general the diet quality indices and their components were unstable (r<0.50). CONCLUSIONS: PAL and the majority of the fitness components remained stable, while diet quality was unstable over 10 years. For unstable parameters such as diet quality measurements are needed at both time points in prospective research.

Effect of oral intake of choline-stabilized orthosilicic acid on skin, nails and hair in women with photodamaged skin.

Chronic exposure of the skin to sunlight causes damage to the underlying connective tissue with a loss of elasticity and firmness. Silicon (Si) was suggested to have an important function in the formation and maintenance of connective tissue. Choline-stabilized orthosilicic acid ("ch-OSA") is a bioavailable form of silicon which was found to increase the hydroxyproline concentration in the dermis of animals. The effect of ch-OSA on skin, nails and hair was investigated in a randomized, double blind, placebo-controlled study. Fifty women with photodamaged facial skin were administered orally during 20 weeks, 10 mg Si/day in the form of ch-OSA pellets (n=25) or a placebo (n=25). Noninvasive methods were used to evaluate skin microrelief (forearm), hydration (forearm) and mechanical anisotropy (forehead). Volunteers evaluated on a virtual analog scale (VAS, "none=0, severe=3") brittleness of hair and nails. The serum Si concentration was significantly higher after a 20-week supplementation in subjects with ch-OSA compared to the placebo group. Skin roughness parameters increased in the placebo group (Rt:+8%; Rm: +11%; Rz: +6%) but decreased in the ch-OSA group (Rt: -16%; Rm: -19%; Rz: -8%). The change in roughness from baseline was significantly different between ch-OSA and placebo groups for Rt and Rm. The difference in longitudinal and lateral shear propagation time increased after 20 weeks in the placebo group but decreased in the ch-OSA group suggesting improvement in isotropy of the skin. VAS scores for nail and hair brittleness were significantly lower after 20 weeks in the ch-OSA group compared to baseline scores. Oral intake of ch-OSA during the 20 weeks results in a significant positive effect on skin surface and skin mechanical properties, and on brittleness of hair and nails.

Changes in weight, body composition and physical fitness after 1.5 years at university.

BACKGROUND/OBJECTIVES: This study examined changes in Belgian students' weight, body composition and physical fitness after 1.5 years at university. Furthermore, this study investigated whether these changes differed by gender and weight status. SUBJECTS/METHODS: In this longitudinal study, 172 students' weight, body mass index (BMI) and waist circumference (WC) were objectively measured, whereas fat%, fat mass, fat-free mass, dynamic leg strength, handgrip strength, hamstring flexibility and cardiorespiratory fitness were estimated using validated instruments. Measurements were conducted at the start of the first semester (T0), after the first semester (T1) and after 1.5 years (T2) at university. RESULTS: Female students' weight and BMI did not change, whereas male students gained 2.7 kg of weight and showed a 0.7 kg/m(2) BMI increase after 1.5 years. After the first semester, an increase in fat% was observed in the total group of students, whereas this time effect did not remain significant when comparing T0 and T2. In contrast to females, increases in 2.1 kg of fat-free mass and 1.8 cm of WC were found in males after 1.5 years. Higher baseline BMI and WC predicted greater BMI and fat% increases in males. Handgrip strength improved for both sexes, whereas no changes in other physical fitness components were found across the 1.5-year period. CONCLUSIONS: The greatest weight and BMI gains as well as unfavourable changes in body composition were found in male students with higher baseline BMI and WC. The observed changes in body composition did not cohere with changes in physical fitness.

Growth, development, and physical fitness of Flemish vegetarian children, adolescents, and young adults.

This study was designed to assess average daily dietary intakes of energy in 82 vegetarian children (group A: 6- 9-y-old girls and 6-11-y-old boys), adolescents (group B: 10- 15-y-old girls and 12-17-y-old boys), and young adults (group C: 16-30-y-old females and 18-30-y-old males) and included determination of height and weight; triceps, suprailiac, and calf skinfold thicknesses; puberty ratings; and physical fitness. Dietary energy intake was lower than recommended values in all 3 groups. Height and weight did not differ significantly from the reference data except in group B, which had significantly lower heights and weights and lower body mass indexes (P<0.05). Triceps and suprailiac skinfold thicknesses were lower in all age groups, whereas the calf skinfold thickness was only significantly lower in the 10-15-y-old girls (P<0.05). The vegetarian children were as physically fit as the reference group. The vegetarian adolescent boys and girls and the young adults scored significantly lower on the standing long jump and 30-s sit-up (P<0.05). The vegetarian subjects of groups B and C recovered significantly faster from the step test (P<0.05). Puberty ratings plotted on percentile graphs showed that all vegetarian subjects, except for 1 girl, were within the normal developmental range. We conclude that, within the limits of this study, vegetarian subjects have lower relative body weights and skinfold thicknesses in adolescence than do nonvegetarians. They scored lower on the strength tests and better on the cardiorespiratory test when compared with reference values. The growth and maturation status of the vegetarian population were within the normal range.

There is no influence of a temperature rise on in vivo adsorption of UV filters into the stratum corneum.

Temperature influences the stratum corneum adsorption of several topically applied compounds. This study was designed to evaluate the influence of the temperature on the stratum corneum adsorption of 3 UV filters. The UV filters were solubilized in two vehicles, an emulsion gel and petroleum jelly and applied at respectively, 31 and 40 degrees C during 30 min. In vivo stratum corneum UV filter content was measured using the tape stripping method. Similar amounts of UV filter were detected in the stratum corneum when comparing applications at the different temperatures. Application of the UV filters in the emulsion gel resulted in higher stratum corneum UV filter concentrations compared with application in the petroleum jelly. The application temperature did not influence the stratum corneum adsorption of the tested UV filters while the nature of the vehicle significantly influenced the amount of UV filters recovered from the stratum corneum.

In vitro percutaneous penetration through hairless rat skin: influence of temperature, vehicle and penetration enhancers.

Theoretically, a positive relation is expected between skin temperature and the percutaneous penetration of topically applied substances. The aim of the present study was to evaluate the influence of the temperature on the in vitro percutaneous penetration of dihydrotestosterone. Hairless rat skin was mounted in static diffusion cells placed in a water bath at different temperatures (28.6, 35.1 and 38.2 degrees C, respectively). Different vehicles were tested as well as the addition of penetration promoting molecules such as oleic acid and limonene. A saline buffer was used as the receptor phase. Penetration through the skin was evaluated by means of scintillation counting of the radiolabelled dihydrotestosterone. Experiments were followed for a period of 29 h. The total amount of penetrant, dihydrotestosterone, as well as the flux, were calculated from these kinetics. Our results demonstrate a temperature effect with the highest penetration at 38.2 degrees C. The vehicle was also found to influence the penetration of dihydrotestosterone in a significant way. Furthermore, limonene presented better penetration promoting properties compared with oleic acid.

Quantitative evaluation of skin surface lipids.

More than 50 years of noninvasive studies of epidermal and sebaceous lipids has revealed a vast amount of information concerning secretion and regulation of SSLs. The first techniques developed (solvent extraction and cigarette paper) required very long experimental procedures to obtain valuable parameters; however, a great part of the knowledge on SSL production and regulation was obtained by these pioneers. Because of the difficulties encountered in these multistep procedures, applicability was restricted to a limited number of research centers. The sampling procedures in the newly developed techniques are significantly reduced and are followed by a fast and accurate evaluation. Moreover, the new sampling procedures permit us to study other aspects of sebum secretion, as demonstrated with the Sebutape method. When using photometric techniques an estimate of the SSL can be obtained within minutes (casual level measurements). After such a screening procedure, more standardized parameters can be accurately determined. Whatever the parameter under investigation, strictly controlled experimental procedures are required. Control of temperature and relative humidity of the experimental room, of the acclimatization periods, and of the volunteers during the collection periods is of capital importance. The studies discussed in this article clearly demonstrate the applicability of the new techniques not only for research and cosmetic purposes but also for clinical use.

Skin color measurements: comparison between three instruments: the Chromameter(R), the DermaSpectrometer(R) and the Mexameter(R).

BACKGROUND/AIMS: Two types of skin reflectance instruments are available nowadays for the determination of skin color: a tristumulus colorimeter (Chromameter from Minolta) using the CIE L*a*b* color system and the narrow-band simple reflectance meters (DermaSpectrometer from Cortex and Mexameter from Courage-Khazaka) using the erythema/melanin indices. The purpose of this study was to compare the capabilities of the three instruments (sensitivity, repeatability and correlation) in vitro and in vivo. METHODS: Comparative color measurements were carried out first in vitro on standardized color charts and subsequently in vivo on different skin areas in human volunteers. Skin color changes induced by various physico-chemical treatments were also quantitatively evaluated with the three instruments. RESULTS: The in vitro and in vivo repeatabilty as well as the sensitivity of the three instruments are rather good. Erythema and skin blanching could be readily quantified by the increase of the a* parameter and of the erythema indices of the simple reflectance meters. Natural UV tanning and artificial chemical tanning could be measured by the decrease of L* and increase of b* and of the melanin indices. CONCLUSION: The Chromameter and the two narrow-band reflectance instruments were able to characterize skin color and to quantify small skin color changes. Moderate to high significant linear correlations could be established between the CIE L*a*b* color parameters and the erythema/melanin indices.

Efficacy of topical treatment of pigmentation skin disorders with plant hydroquinone glucosides as assessed by quantitative color analysis.

Hydroquinone is a well known reagent used in the treatment of pigmentation disorders. The instability of the quinones and the required active concentration make topical treatment rather difficult. We tested the efficacy of an ascorbate-phytohydroquinone complex that inhibits the synthesis of melanin and promotes the degradation of the existing melanin. Lentigo senile lesions were evaluated before and after 1 month of treatment. Objective skin color evaluation was performed instrumentally. After one month of treatment, a clear depigmentation of the macules was measured. None of the volunteers reported any side effects from the prolonged treatment with the hydroquinone containing product.