Text messaging (SMS) as a tool to facilitate weight loss and prevent metabolic deterioration in clinically healthy overweight and obese subjects: a randomised controlled trial

Figures & data

Figure 1. Participant flow and follow-up.

Table 1. Baseline characteristics by arm, Riga, Latvia, 2012.

Variables	Intervention n = 63	Control group n = 60
Age, years	36.6 (4.2)	37.0 (4.3)
Male, n (%)	30 (48)	28 (47)
Smokers, n (%)	22 (35)	17 (28)
Pack years, median (IQR)	1.0 (0–7.5)	0.8 (0–10.0)
Hepatic steatosis on CT, n (%)	25 (40)	22 (37)
Hepatic density (HV), median (IQR)	57.3 (51.3–60.7)	56.6 (53.1–61.8)
Subcutaneous fat at L4/L5 level (cm)	3.4 (1.2)	3.4 (1.1)
Intense physical activity, n (%)	4 (6)	8 (13)
Unfavourable family anamnesis, n (%)	11 (17)	7(12)
Usually following diet recommendations, n (%)	12 (19)	10 (17)
Alcohol >7 drinks per week, n (%)	3 (5)	1 (2)
Weight (kg)	94.9 (4.7)	95.0 (15.7)
BMI (kg/m^2)	31.9 (4.2)	32.1 (4.4)
Waist circumference, cm	100.0 (11.6)	99.2 (11.3)
Hip circumference, cm	114.2 (7.3)	113.2(8.9)
Waist–hip ratio	0.9 (0.1)	0.9 (0.1)
TC (mmol/l)	5.4 (1.0)	5.5 (1.1)
HDL-C (mmol/l)	1.4 (0.3)	1.4 (0.4)
Dyslipidaemia, n (%)	29 (46)	27 (45)
LDL-C, mmol/l	3.3 (0.9)	3.5(1.0)
TG (mmol/l), median (IQR)	1.5 (0.9–1.9)	1.3 (0.9–1.8)
TC/HDL-C ratio	4.0 (1.0)	4.2 (1.2)
TG/HDL-C ratio, median (IQR)	1.1 (0.6–1.6)	0.9 (0.6–1.7)
Glucose, mmol/l	5.2 (0.5)	5.2 (0.5)
Insulin (μU/ml), median (IQR)	11.4 (8.5–18.2)	11.7 (8.3–15.3)
AST, U/L	26 (22–30)	24 (21–28)
ALT, U/L	28 (22–43)	27 (20–38)
AST/ALT ratio, median (IQR)	0.9 (0.7–1.1)	0.9 (0.7–1.1)

BMI: body mass index; TC: total cholesterol; HDL-C: high density lipoprotein cholesterol; LDL-C: low density lipoprotein cholesterol; TG: triglycerides; HOMA IR: homeostasis model assessment of insulin resistance; AST: aspartate aminotransferase; ALT: alanine aminotransferase.

Values are mean (SD) for numerical variables or number (%) for categorical variables unless stated otherwise.

Table 2. Results of bivariate analysis of the mean change (SD) of the two arms and the mean differences (SMS-Control) in the outcome variables 1 year after the intervention.

Variables	SMS Group mean change (SD) n = 63	Control mean change (SD) n = 60	Mean difference of the change	95% CI of the mean difference	Effect size Hedge’s g	p Value
Weight, kg	–2.40 (7.27)	1.02 (3.97)	–3.42	–5.5, –1.3	0.58	.002
BMI, kg/m^2	–0.81 (2.51)	0.33 (1.35)	–1.14	–1.9, –0.41	0.56	.002
Waist C, cm	–5.0 (7.3)	–0.4 (4.91)	–4.6	–6.8, –2.3	0.73	<.001
Hip C, cm	–4.6 (6.0)	–0.6 (4.80)	–4.0	–5.9, –2.0	0.73	<.001
Waist-hip ratio	–0.009 (0.047)	0.002 (0.043)	–0.01	–0.26, 0.006	0.24	.22
TC, mmol/l	–0.10 (0.7)	–0.06 (0.69)	–0.04	–0.29, 0.21	0.06	.73
HDL-C, mmol/l	0.04 (0.23)	0.02 (0.21)	0.14	–0.65, 0.09	0.26	.73
LDL-C, mmol/l	–0.07 (0.54)	–0.09 (0.60)	–0.02	–0.22, 0.18	0.04	.84
TG, mmol/l	–0.13 (0.77)	0.10 (0.85)	0.23	–0.06, 0.52	0.28	.11
TC/HDL-C ratio	–0.13 (0.57)	–0.12 (0.39)	0.15	–0.16, 0.19	0.02	.87
TG/HDL-C ratio	–0.13 (0.71)	0.07 (0.68)	0.20	–0.46, 0.45	0.28	.11
Glucose, mmol/l	0.18 (0.50)	0.17 (0.51)	–0.01	–0.19, 0.17	0.02	.94
Insulin, μU/ml	–0.38 (5.40)	2.05 (4.82)	2.43	0.6, 4.3	0.47	.01

BMI: body mass index; waist C: waist circumference; hip C: hip circumference; TC: total cholesterol; HDL-C: high density lipoprotein cholesterol; LDL-C: low density lipoprotein cholesterol; TG: triglycerides.

Table 3. Results of multiple linear regression analyses of the outcome variables controlling for age and gender.

Variable	B	SE	t	p Value	95% CI for B	R^2
Weight						.075
Age	0.074	0. 128	0.578	.564	–0.18, 0.33
Gender	0.749	1.079	0.694	.489	–1.4, 2.9
Group	–3.175	1.079	–2.944	.004	–5.3, –1.04
BMI						.078
Age	0.026	0.044	0.591	.56	–0.06, 0.11
Gender	0.162	0.369	0.438	.67	–0.57. 0.89
Group	–1.13	0.369	–3.056	.003	–1.86, –0.40
Waist circumference						.13
Age	0.059	0.134	0.44	.66	–0.21,0.32
Gender	1.031	1.13	0.91	.34	–1.21, 3.30
Group	–4.56	1.13	–4.03	<.001	–6.8, –2.3
Hip circumference						.12
Age	–0.007	0.117	–0.06	.95	–0.24, 0.22
Gender	0.87	0.99	.88	.38	–1.08, 2.82
Group	–4.0	0.99	–4.02	<.001	–5.9, –2.0
Insulin						.06
Age	0.041	0.11	0.37	.70	–0.18, 0.26
Gender	–0.83	0.93	–0.89	.40	–2.7, 1.01
Group	–2.41	0.93	–2.59	.01	–4.25, –.0.57

B: regression coefficient; SE: standard error; CI: confidence interval.

Table 4. Results of the post-intervention survey filled in by the intervention group regarding text messaging.

Question	Mean^a	Never, %	Seldom, %	50/50, %	Often, %	Always, %
Did you read the text message?	4.73	0.0	1.6	4.8	12.7	81.0
Did you understand the text message?	4.84	0.0	0.0	1.6	12.7	85.7
Did you save text message?	4.08	9.5	4.8	12.7	14.3	58.7
Did you gain new knowledge by the text message?	3.43	1.6	15.9	39.7	23.8	19.0
Did you try to implement the advice of the text message?	3.11	0.0	23.8	50.8	15.9	9.5
Did you search for more relevant information after reading the text message?	1.78	49.2	33.3	11.1	3.2	3.2
Did you feel disturbed by getting the text message?	1.17	88.9	7.9	1.6	0.0	1.6
Did you feel irritated by getting the text message?	1.16	90.5	6.3	1.6	0.0	1.6

^a Scale from 1 to 5 was used: 1 – never, 2 – seldom, 3 – 50/50, 4 – often, 5 – always.