Table 2.

Descriptive characteristics of studies included in the meta-analysis of validity of resonance Raman spectroscopy

Reference	No. of participants	Pearson correlation coefficient	Mean age ± SD (years)a	Race/ethnicity, no. (%)	Biological sex, no. (%)	Mean BMI ± S (kg/m2)	Plasma/serum, carotenoids assessed
Studies among adults
Morgan et al 201976	157	r = 0.698   P < 0.0001	58.56 ± 9.49	Non-Hispanic white: 150 (95.5)   Other: 6 (3.8)   Not reported: 1 (0.6)	Female: 157 (100)	Mean BMI: 35.72 ± 6.48	Serum: total carotenoids, specific carotenoids were not named.
Jahns et al 201977	52	r = 0.77   P < 0.001	49.4 ± 0.8 (SE)	Non-Hispanic white: 50 (96)	Female: 52 (100)	Mean BMI: 26.5 ± 0.6 (SE)   Overweight: 17 (33%)   Obese: 12 (23%)	Plasma: α-, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin.
Rensburg et al 201679	61	r = 0.72   P < 0.001	Overall populationa:   Males: 40.6 ± 12.2   Females: 42.8 ± 12.0	Overall populationa:   Non-Hispanic White: 78 (96.3)   Indian: 1 (1.2)   African: 2 (2.5)	Overall populationa:   Male : 19 (23)   Female: 62 (77)	Mean BMI, males: 25.0 ± 2.2; females: 23.7 ± 2.7	Serum; lutein/zeaxanthin, β-carotene, lycopene.
Zidichouski et al 200980	372	r = 0.82   P = 0.001	33.4 ± 10.0	Not provided	Male: 199 (53)   Female: 173 (47)	Not provided.	Serum: α-, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin.
Jahns et al 201478	29	r = 0.61   P < 0.001	32.1 ± 2.5 (SE)	Non-Hispanic White: 28 (96)	Male: 9 (31)   Female: 20 (69)	Mean BMI: 23.6 ± 0.6 (SE)	Plasma: α-, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin.
Bernstein et al 201281	45	r = 0.4727   P = 0.0010	Overall populationa: 77.4 ± 7.7 (range, 50–85)	Not provided.	Overall populationa:   Male: 24 (45)   Female: 29 (55)	Not provided.	Serum: oxolutein, lutein, zeaxanthin, β-cryptoxanthin, α-carotene, β-carotene, and lycopene.
Henriksen et al 201371	38b	r = 0.63   P < 0.001	Not provided	Mothers of normal-weight infants:   Non-Hispanic White: 53   Latino: 43   Asian: 3   Mothers of infants with IUGR:   Non-Hispanic White: 30   Latino: 60   Asian: 10	Female: 38 (100)	Not provided.	Serum: lutein, oxolutein, zeaxanthin, β-cryptoxanthin, α-carotene, β-carotene, and lycopene.
Mayne et al 201015	28	r = 0.62   P = 0.006	Overall populationa: 37.0 (no SD reported; median: 33 y)	Overall populationa:   Non-Hispanic White: 62 (83.8)   Non-White: 12 (16.2)	Overall populationa:   Male: 28 (38)   Female: 46 (62)	Overall populationa:   Underweight: 4 (5.4%)   Healthy weight: 45 (60.8%)   Overweight: 20 (27.0%)   Obese: 5 (6.8%)	Plasma: lutein, zeaxanthin, β-cryptoxanthin, β-carotene, and lycopene
Conrady et al 201782	88	r = 0.722   P < 0.0001	59 ± 17 (range, 13–90)	Non-Hispanic White: 74 (84)   African: 1 (1)   Asian: 1 (1)   Hispanic: 1 (1)   Multinational: 1 (1) Not recorded: 10 (11)	Male: 39 (44)   Female: 49 (56)	Not provided	Serum: lutein, zeaxanthin, lutein + zeaxanthin, and total carotenoids, specific carotenoids were not named
Meinke et al 201074	22	r = 0.77	Experimental group: 40.5 (range, 22–59; median, 42 y)   Placebo group:   34.7 (range, 25–49; median, 29 y)	Not provided.	Experimental group:   Male: 6 (54)   Female: 5 (46)   Placebo group:   Male: 8 (73)   Female: 3 (27)	Experimental group: 27.0 (range, 18–35; median, 29.1)   Placebo group: 25.0 (range, 19–32; median, 26.1)	Serum: lutein, zeaxanthin, α-carotene, β-carotene, β-cryptoxanthin, and lycopene
Perrone et al 201675	71	r = 0.450   P< 0.0001	Age range, 36–74	Not provided	Female: 71 (100)	27.06 ± 2.84	Serum: lycopene
Studies among children
Aguilar et al 201469	45	r = 0.70	10.5 (range, 5–17)	Non-Hispanic White: 34 (76)   Hispanic: 7 (16)   Asian: 3 (6)   Pacific Islander: 1 (2)	Female: 25 (55)   Male: 20 (45)	Underweight (<5th percentile): 4 (8%)   Normal weight (5th to <85th percentile): 34 (76%)   Overweight (>85th percentile): 7 (16%)	Serum: β-carotene, lycopene, and lutein
Bernstein et al 201370	n = 37c	r = 0.78   P< 0.0001	Infants and children < 7 y	Non-Hispanic White: 30 (81.1)   Hispanic: 4 (10.8)   Multiracial: 3 (8.1)	Male: 16 (43)   Female: 21 (57)	Not provided	Serum: total carotenoids, specific carotenoids were not named other than lutein/zeaxanthin
Henriksen et al 201371 (Infants: normal weight and IUGR)	N = 40*	r = 0.39   P = 0.021	Normal weight: gestational age:   37–38 wk: 43%   39–40+ wk: 57%   IUGR: gestational age:   37–38 wk: 75%   39–40+ wk: 25%	Normal weight:   Non-Hispanic White: 53   Latino: 43   Asian: 3   IUGRc:   Non-Hispanic White: 33   Latino: 58   Asian: 8	Normal weight:   Male: 53   Female: 47   IUGR:   Male: 42   Female: 58	Birth weight <10th percentile for age: 10 (33.3%)	Serum: lutein, oxolutein, zeaxanthin, β-cryptoxanthin, α-carotene, β-carotene, and lycopene
Ermakov et al 201372	32	r = 0.75	Infants aged 1 d to 6 y	Non-Hispanic White: 32 (100)	Not provided	Not provided	Serum: total carotenoids, specific carotenoids were not named
Nguyen et al 201573	38	r = 0.62   P < 0.001	11.2 ± 0.5 (range, 10–12)	Not provided	Male: 11 (29)   Female: 27 (71)	BMI percentile ($\overline{x}$ + SD) 73.3 ± 26.3   Normal weight (5th to <85th percentile): 19 (50%)   Overweight (85th to <95th percentile): 9 (23.7%)   Obese (>95th percentile): 10 (26.3%)	Plasma: α-carotene, β-carotene, lutein, zeaxanthin, and lycopene

^aNumbers given for the overall population but not for the subset of individuals for which both resonance Raman spectroscopy–assessed skin carotenoids and plasma/serum carotenoids were available.

^bControl (healthy weight infants): 37 wk gestation or older: n = 30; IUGR: birth weight <10th percentile for age: n = 10. In this study, there were 2 sets of twins, so there are 38 mothers and 40 infants.

^cAll demographic data were obtained from supplementary materials found at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3680006/bin/supp_13-11891_IOVS-13-11891-s01.pdf  or  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3680006/bin/supp_54_6_4034__index.html.⁷⁰

Abbreviations: BMI, body mass index; IUGR, intrauterine growth restriction.