Niacin improves adiponectin secretion, glucose tolerance and insulin sensitivity in diet-induced obese rats

Figures & data

Table 1 Composition of experimental diets (unit: g/Kg).

Components	Control	HFD	NSD
Corn flour	529.5	330.5	329.5
Casein	200	200	200
Sucrose	100	100	100
Soybean oil	70	40	40
Cellulose	50	50	50
Mineral mix	35	35	35
Vitamin mix	10	10	10
L-cystine	3	3	3
Choline	2.5	2.5	2.5
Butter	0	229	229
Niacin	0	0	1
Total	1000	1000	1000

Table 2 Body weight, weight gain and food intake in control and experimental rats.

Parameters	Timeline	Control	Obese	Obese + niacin
Body weight (g)	Baseline	51.00 ± 1.32	52.00 ± 1.23	49.14 ± 1.53
	4 weeks	86.14 ± 4.72	115.88 ± 3.88^**	111.42 ± 8.51^**
	8 weeks	131.14 ± 5.91	176.29 ± 5.26^**	166.4 ± 9.61^**
	14 weeks	194.42 ± 4.64	273.33 ± 4.47^***	212.4 ± 8.02^###
Food intake (g)	Baseline	62.57 ± 3.24	71.14 ± 1.86	72.14 ± 4.50
	4 weeks	90.71 ± 3.63	94.29 ± 2.10	96.57 ± 2.99
	8 weeks	100.43 ± 2.27	104.71 ± 2.76	107.57 ± 3.79
	14 weeks	122.86 ± 2.14	122.86 ± 2.64	128.43 ± 3.73
% Weight gain	4 weeks	68.9	122.84	126.74
	8 weeks	157.13	239.01	238.62
	14 weeks	281.21	425.63	332.23

Results are presented as mean ± SEM, n = 6.

* P < 0.05,

** P < 0.01 and

*** P < 0.001 compared with control group;

### P < 0.001 compared with obese group.

Fig. 1 Glucose response curves during oral-glucose-tolerance test in control and experimental rats. Each point represents the mean, n = 6.

Fig. 2 Glucose response curves during insulin-tolerance test in control and experimental rats. Each point represents the mean, n = 6.

Fig. 3 AUC for OGTT and ITT in control and experimental rats. Results are presented as mean ± SEM, n = 6. *P < 0.05 compared with control group; ^#P < 0.05 compared with obese group.

Table 3 Weight of epididymal, omental and retroperitoneal fat pads in control and experimental rats.

Parameters	Control	Obese	Obese + niacin
Epididymal fat pad (g)	0.93 ± 0.04	1.15 ± 0.05^*	1.01 ± 0.07
Epididymal fat pad/body weight ratio	0.48	0.38	0.48
Omental fat pad (g)	0.85 ± 0.06	1.18 ± 0.05^**	0.95 ± 0.05^##
Omental fat pad/body weight ratio	0.44	0.4	0.46
Retroperitoneal fat pad (g)	0.98 ± 0.06	1.29 ± 0.09^*	1.09 ± 0.09
Retroperitoneal fat pad/body weight ratio	0.5	0.47	0.51

Results are presented as mean ± SEM, n = 6.

* P < 0.05 and

** P < 0.01 compared with control group;

## P < 0.01 compared with obese group.

Fig. 4 Plasma concentrations of CHOL, TRIG, HDL and LDL in control and experimental rats. Results are presented as mean ± SEM, n = 6. *P < 0.05 compared with control group; ^#P < 0.05 compared with obese group.

Table 4 Concentration of insulin and adiponectin in control and experimental rats.

Parameters	Control	Obese	Obese + niacin
Insulin (pmol/l)	693 ± 35	1076 ± 98^**	842 ± 64^#
Adiponectin (ng/ml)	986 ± 87	651 ± 58^***	813 ± 72^##

Results are presented as mean ± SEM, n = 6.

* P < 0.05,

** P < 0.01 and

*** P < 0.001 compared with control group;

# P < 0.05 and

## P < 0.01 compared with obese group.